libutils: util.h: fix the GENMASK_32(h, l) macro

The macro has a problem when it is used in an assembly file:
.e.g ".word GENMASK_32(15, 8)" will be compiled to ".word 0xffffff00"

The issue is caused by the compiler always treating ~0 as a 64-bit
value. Fix it by replacing '~UINT32_C(0)' with 'UINT32_C(0xffffffff)'.

Signed-off-by: Tony Han <tony.han@microchip.com>
Acked-by: Etienne Carriere <etienne.carriere@foss.st.com>
Reviewed-by: Jens Wiklander <jens.wiklander@linaro.org>

lib/libutils/ext/include/util.h

@@ -135,7 +135,8 @@
  * GENMASK_64(39, 21) gives us the 64bit vector 0x000000ffffe00000.
  */
 #define GENMASK_32(h, l) \
-	(((~UINT32_C(0)) << (l)) & (~UINT32_C(0) >> (32 - 1 - (h))))
+	((UINT32_C(0xffffffff) << (l)) & \
+	 (UINT32_C(0xffffffff) >> (32 - 1 - (h))))
 
 #define GENMASK_64(h, l) \
 	(((~UINT64_C(0)) << (l)) & (~UINT64_C(0) >> (64 - 1 - (h))))