src: Report byte-sized access for GPE0

According to the ACPI specification, version 6.3:

    OSPM accesses GPE registers through byte
    accesses (regardless of their length).

So, reporting dword-sized access is wrong and means nothing anyway.

Tested on Asus P8Z77-V LX2, Windows 10 still boots.

Change-Id: I965131a28f1a385d065c95f286549665c3f9693e
Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/42671
Reviewed-by: Matt DeVillier <matt.devillier@gmail.com>
Reviewed-by: Patrick Rudolph <siro@das-labor.org>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/soc/intel/common/block/acpi/acpi.c b/src/soc/intel/common/block/acpi/acpi.c
index c497399..3265131 100644
--- a/src/soc/intel/common/block/acpi/acpi.c
+++ b/src/soc/intel/common/block/acpi/acpi.c
@@ -157,7 +157,7 @@
 	fadt->x_gpe0_blk.space_id = ACPI_ADDRESS_SPACE_IO;
 	fadt->x_gpe0_blk.bit_width = fadt->gpe0_blk_len * 8;
 	fadt->x_gpe0_blk.bit_offset = 0;
-	fadt->x_gpe0_blk.access_size = ACPI_ACCESS_SIZE_DWORD_ACCESS;
+	fadt->x_gpe0_blk.access_size = ACPI_ACCESS_SIZE_BYTE_ACCESS;
 	fadt->x_gpe0_blk.addrl = fadt->gpe0_blk;
 	fadt->x_gpe0_blk.addrh = 0;