src/southbridge/amd/*/*/fadt.c: Use macro for access_size

Change-Id: I316abf6626adabeecdf9639712ab3bf64e3cbe83
Signed-off-by: Elyes HAOUAS <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/44519
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
diff --git a/src/southbridge/amd/cimx/sb800/fadt.c b/src/southbridge/amd/cimx/sb800/fadt.c
index 3868d24..a5c27d6 100644
--- a/src/southbridge/amd/cimx/sb800/fadt.c
+++ b/src/southbridge/amd/cimx/sb800/fadt.c
@@ -101,7 +101,7 @@
 	fadt->x_pm1a_cnt_blk.space_id = ACPI_ADDRESS_SPACE_IO;
 	fadt->x_pm1a_cnt_blk.bit_width = 16;
 	fadt->x_pm1a_cnt_blk.bit_offset = 0;
-	fadt->x_pm1a_cnt_blk.access_size = 0;
+	fadt->x_pm1a_cnt_blk.access_size = ACPI_ACCESS_SIZE_UNDEFINED;
 	fadt->x_pm1a_cnt_blk.addrl = PM1_CNT_BLK_ADDRESS;
 	fadt->x_pm1a_cnt_blk.addrh = 0x0;