src: Remove unused 'include <cbmem.h>'

Change-Id: Ib41341b42904dc3050a97b70966dde7e46057d6b
Signed-off-by: Elyes HAOUAS <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/43362
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>

src/soc/amd/picasso/mca.c

@@ -7,7 +7,6 @@
 #include <console/console.h>
 #include <arch/bert_storage.h>
 #include <cper.h>
-#include <cbmem.h>
 
 struct mca_bank {
 	int bank;