NX: Mutex and thread NX ready (#270)

Co-authored-by: Aleš Mlakar <[email protected]>

src/mutex.cpp

@@ -17,7 +17,8 @@
 	|| BX_PLATFORM_IOS     \
 	|| BX_PLATFORM_OSX     \
 	|| BX_PLATFORM_PS4     \
-	|| BX_PLATFORM_RPI
+	|| BX_PLATFORM_RPI	   \
+	|| BX_PLATFORM_NX
 #	include <pthread.h>
 #elif  BX_PLATFORM_WINDOWS \
 	|| BX_PLATFORM_WINRT   \

src/thread.cpp

@@ -21,7 +21,8 @@
 	|| BX_PLATFORM_IOS     \
 	|| BX_PLATFORM_OSX     \
 	|| BX_PLATFORM_PS4     \
-	|| BX_PLATFORM_RPI
+	|| BX_PLATFORM_RPI	   \
+	|| BX_PLATFORM_NX
 #	include <pthread.h>
 #	if defined(__FreeBSD__)
 #		include <pthread_np.h>