Assorted Windows-on-ARM fixes

Common/ArmCPUDetect.cpp

@@ -208,6 +208,13 @@ void CPUInfo::Detect()
 #endif
 	strcpy(brand_string, "Apple A");
 	num_cores = 2;
+#elif PPSSPP_PLATFORM(UWP)
+	strcpy(brand_string, "Unknown");
+	isVFP3 = true;
+	isVFP4 = false;
+	SYSTEM_INFO sysInfo;
+	GetSystemInfo(&sysInfo);
+	num_cores = sysInfo.dwNumberOfProcessors;
 #else // !PPSSPP_PLATFORM(IOS)
 	strcpy(brand_string, "Unknown");
 	num_cores = 1;