Restore ability to handle non-hex string in device discovery vendor/device id. (microsoft#25427)

### Description
<!-- Describe your changes. -->
Restore ability to handle "VEN_QCOM" from an ACPI entry.

### Motivation and Context
<!-- - Why is this change required? What problem does it solve?
- If it fixes an open issue, please link to the issue here. -->

Author: skottmckay

onnxruntime/core/platform/windows/device_discovery.cc

@@ -77,6 +77,29 @@ struct DriverInfo {
   }
 };
 
+bool IsHexString(const std::wstring& str) {
+  for (const wchar_t& c : str) {
+    if (!((c >= L'0' && c <= L'9') || (c >= L'A' && c <= L'F') || (c >= L'a' && c <= L'f'))) {
+      return false;
+    }
+  }
+  return true;
+}
+
+// Converts a wide string ACPI (up to 4 characters) representing a hardware ID component from into a uint32_t.
+// e.g., "QCOM" from "VEN_QCOM". The conversion is done in a little-endian manner, meaning the first character
+// of the string becomes the least significant byte of the integer, and the fourth character
+// becomes the most significant byte.
+uint32_t AcpiWStringToUint32Id(const std::wstring& vendor_name) {
+  uint32_t vendor_id = 0;
+  for (size_t i = 0; i < 4 && i < vendor_name.size(); ++i) {
+    // For little-endian, place each character at the appropriate byte position
+    // First character goes into lowest byte, last character into highest byte
+    vendor_id |= static_cast<unsigned char>(vendor_name[i] & 0xFF) << (i * 8);
+  }
+  return vendor_id;
+}
+
 uint64_t GetDeviceKey(uint32_t vendor_id, uint32_t device_id) {
   return (uint64_t(vendor_id) << 32) | device_id;
 }
@@ -134,25 +157,35 @@ std::unordered_map<uint64_t, DeviceInfo> GetDeviceInfoSetupApi(const std::unorde
         // PCI\VEN_xxxx&DEV_yyyy&...
         // ACPI\VEN_xxxx&DEV_yyyy&... if we're lucky.
         // ACPI values seem to be very inconsistent, so we check fairly carefully and always require a device id.
-        const auto get_id = [](const std::wstring& hardware_id, const std::wstring& prefix) -> uint32_t {
+        const auto get_id = [](bool is_pci, const std::wstring& hardware_id, const std::wstring& prefix) -> uint32_t {
           if (auto idx = hardware_id.find(prefix); idx != std::wstring::npos) {
             auto id = hardware_id.substr(idx + prefix.size(), 4);
+
             if (id.size() == 4) {
-              return static_cast<uint32_t>(std::stoul(id, nullptr, 16));
+              if (is_pci || IsHexString(id)) {
+                // PCI entries have hex numbers. ACPI might.
+                return static_cast<uint32_t>(std::stoul(id, nullptr, 16));
+              } else {
+                // ACPI can have things like "VEN_QCOM". Fallback to using this conversion where the characters
+                // are converted in little-endian order.
+                return AcpiWStringToUint32Id(id);
+              }
             }
           }
 
           return 0;
         };
 
-        // Processor ID should come from CPUID mapping.
+        const bool is_pci = std::wstring(buffer, 3) == std::wstring(L"PCI");
+
         if (guid == GUID_DEVCLASS_PROCESSOR) {
+          // Processor ID should come from CPUID mapping.
           vendor_id = CPUIDInfo::GetCPUIDInfo().GetCPUVendorId();
         } else {
-          vendor_id = get_id(buffer, L"VEN_");
+          vendor_id = get_id(is_pci, buffer, L"VEN_");
         }
 
-        device_id = get_id(buffer, L"DEV_");
+        device_id = get_id(is_pci, buffer, L"DEV_");
 
         // Won't always have a vendor id from an ACPI entry.  ACPI is not defined for this purpose.
         if (vendor_id == 0 && device_id == 0) {