mb/google/nissa/var/pirrha: Turn off SD card power signal in s0ix

Turn off GPP_H13 (EN_PP3300_SD_X) in s0ix for power saving. It reduces
about 3mW of power consumption in s0ix on pirrha proto board.

BUG=b:300845527
TEST=Built and verified GPP_H13 voltage was 0V in s0ix.
     Also verified SD card worked after s0ix for 20 times.

Change-Id: I5ec53820276e50f5b8b01584595118cf2dc4c95c
Signed-off-by: Seunghwan Kim <sh_.kim@samsung.corp-partner.google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/77998
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Paul Menzel <paulepanter@mailbox.org>
Reviewed-by: Derek Huang <derekhuang@google.com>
Reviewed-by: Eric Lai <ericllai@google.com>

src/mainboard/google/brya/variants/pirrha/Makefile.inc

@@ -4,4 +4,5 @@ bootblock-y += gpio.c
 romstage-y += memory.c
 
 ramstage-$(CONFIG_FW_CONFIG) += fw_config.c
+ramstage-$(CONFIG_FW_CONFIG) += variant.c
 ramstage-y += gpio.c

src/mainboard/google/brya/variants/pirrha/include/variant/gpio.h

@@ -5,4 +5,6 @@
 
 #include <baseboard/gpio.h>
 
+#define SD_CARD_POWER		GPP_H13
+
 #endif

src/mainboard/google/brya/variants/pirrha/variant.c

@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <chip.h>
+#include <baseboard/variants.h>
+#include <variant/gpio.h>
+#include <acpi/acpigen.h>
+
+void variant_generate_s0ix_hook(enum s0ix_entry entry)
+{
+	return;
+
+	if (entry == S0IX_ENTRY)
+		acpigen_soc_clear_tx_gpio(SD_CARD_POWER);
+	else if (entry == S0IX_EXIT)
+		acpigen_soc_set_tx_gpio(SD_CARD_POWER);
+}