soc/intel/xeon_sp/cpx: Set SLEEP_BUTTON flag in ACPI FADT

Keep SLEEP_BUTTON flag in ACPI FADT to indicate that no sleep button
is present on Cooperlake platform.

Change-Id: I2ce435a7bda780b2d2ed00be3f3a8a080c4434ab
Signed-off-by: Morgan Jang <Morgan_Jang@wiwynn.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/46833
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
diff --git a/src/soc/intel/xeon_sp/cpx/soc_acpi.c b/src/soc/intel/xeon_sp/cpx/soc_acpi.c
index 8820517..d60684b 100644
--- a/src/soc/intel/xeon_sp/cpx/soc_acpi.c
+++ b/src/soc/intel/xeon_sp/cpx/soc_acpi.c
@@ -53,8 +53,7 @@
 void soc_fill_fadt(acpi_fadt_t *fadt)
 {
 	/* Clear flags set by common/block/acpi/acpi.c acpi_fill_fadt() */
-	fadt->flags &=  ~(ACPI_FADT_SLEEP_BUTTON | ACPI_FADT_SEALED_CASE |
-				ACPI_FADT_S4_RTC_WAKE);
+	fadt->flags &=  ~(ACPI_FADT_SEALED_CASE | ACPI_FADT_S4_RTC_WAKE);
 }
 
 void uncore_inject_dsdt(const struct device *device)