soc/amd/common/block/include/psp_efs: use unsigned type for bitfield

For 1 bit long bit fields an unsigned type should be used. In this case
uint32_t is used instead of a generic unsigned int for both consistency
reasons with the rest of the file and to clarify that the bits will be
packed into a 32 bit memory location.

TEST=Resulting image of a timeless build for google/guybrush results in
identical binary.

Signed-off-by: Felix Held <felix-coreboot@felixheld.de>
Change-Id: Ic630d1709174d90336746bc37da504437c12643c
Reviewed-on: https://review.coreboot.org/c/coreboot/+/58224
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Raul Rangel <rrangel@chromium.org>

src/soc/amd/common/block/include/amdblocks/psp_efs.h

@@ -26,8 +26,8 @@
 
 
 struct second_gen_efs { /* todo: expand for Server products */
-	int gen:1; /* Client products only use bit 0 */
-	int reserved:31;
+	uint32_t gen:1; /* Client products only use bit 0 */
+	uint32_t reserved:31;
 } __attribute__((packed));
 
 /* Copied from coreboot/util/amdfwtool.h */