soc/amd: use KiB and MiB definitions

Use KiB and MiB instead of multiplying/dividing with/by the numeric
value when doing region size calculations.

Signed-off-by: Felix Held <felix-coreboot@felixheld.de>
Change-Id: I56c380190b11aa3214cce31b82974327e3d15000
Reviewed-on: https://review.coreboot.org/c/coreboot/+/59936
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by:  Felix Singer <felixsinger@posteo.net>

src/soc/amd/picasso/agesa_acpi.c

@@ -82,7 +82,7 @@ static unsigned long gen_crat_memory_entries(struct acpi_crat_header *crat,
 			if (memory_base == 0) {
 				current =
 					create_crat_memory_entry(0, 0ull, 0xa0000ull, current);
-				memory_base = (1 * 1024 * 1024);
+				memory_base = 1 * MiB;
 				memory_length = memory_base;
 				new_entries++;
 			}