sb/intel/{bd82x6x|ibexpeak}: Clear flush_* in FADT

Both fields are ignored if WBINVD is set, which is true for all
processors since i486.

Change-Id: Ibad56046e2c1b8595dc31e5861b9fd1fd7d2d6f3
Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Signed-off-by: Christian Walter <christian.walter@9elements.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/34453
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
diff --git a/src/southbridge/intel/bd82x6x/lpc.c b/src/southbridge/intel/bd82x6x/lpc.c
index 987db36..55e2573 100644
--- a/src/southbridge/intel/bd82x6x/lpc.c
+++ b/src/southbridge/intel/bd82x6x/lpc.c
@@ -726,12 +726,12 @@
 	}
 	fadt->p_lvl2_lat = c2_latency;
 	fadt->p_lvl3_lat = 87;
-	fadt->flush_size = 1024;
-	fadt->flush_stride = 16;
+	/* flush_* is ignored if ACPI_FADT_WBINVD is set */
+	fadt->flush_size = 0;
+	fadt->flush_stride = 0;
 	/* P_CNT not supported */
 	fadt->duty_offset = 0;
 	fadt->duty_width = 0;
-
 	fadt->day_alrm = 0xd;
 	fadt->mon_alrm = 0x00;
 	fadt->century = 0x00;