[SYCL][CUDA] Further fixes to CUDA device selection

Fix platform string comparison for CUDA platform detection.
Fix device info platform query so that it uses the device's plugin,
rather than the GlobalPlugin.

Signed-off-by: Alexander Johnston <alexander@codeplay.com>

Author: Alexander Johnston

sycl/source/detail/device_info.hpp

@@ -68,7 +68,7 @@ template <info::device param> struct get_device_info<platform, param> {
     // Use the Plugin from the device_impl class after plugin details
     // are added to the class.
     return createSyclObjFromImpl<platform>(
-        std::make_shared<platform_impl>(result, RT::GlobalPlugin));
+        std::make_shared<platform_impl>(result, Plugin));
   }
 };
 

sycl/source/detail/platform_impl.hpp

@@ -73,7 +73,7 @@ class platform_impl {
   bool is_host() const { return MHostPlatform; };
 
   bool is_cuda() const {
-    const string_class CUDA_PLATFORM_STRING = "NVIDIA_CUDA";
+    const string_class CUDA_PLATFORM_STRING = "NVIDIA CUDA";
     const string_class PlatformName = get_platform_info<string_class, 
                                                   info::platform::name>::get(MPlatform, getPlugin());
     return PlatformName == CUDA_PLATFORM_STRING;