include/cpu/amd/mtrr: fix typo in get_top_of_mem_above_4gb

Add the missing 'b' to the 4gb so that get_top_of_mem_above_4gb is in
line with get_top_of_mem_below_4gb.

Signed-off-by: Felix Held <felix-coreboot@felixheld.de>
Change-Id: Ic9170372d8b0c27d7de3bd04d822c95e2015cb10
Reviewed-on: https://review.coreboot.org/c/coreboot/+/74710
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Fred Reitberger <reitbergerfred@gmail.com>

src/include/cpu/amd/mtrr.h

@@ -70,7 +70,7 @@ static inline uint32_t get_top_of_mem_below_4gb(void)
 	return rdmsr(TOP_MEM).lo;
 }
 
-static inline uint64_t get_top_of_mem_above_4g(void)
+static inline uint64_t get_top_of_mem_above_4gb(void)
 {
 	msr_t msr = rdmsr(TOP_MEM2);
 	return (uint64_t)msr.hi << 32 | msr.lo;