mb/google/corsola: Add an option for SD card initialization

There is no support for SD card on Corsola reference board, so
we add a configuration to disable SD card initialization to
prevent setting GPIOs in a mistaken way.

TEST=build pass
BUG=b:202871018

Signed-off-by: Rex-BC Chen <rex-bc.chen@mediatek.com>
Change-Id: Ia05fd046335c6ce6f9198ddbb7cbda2afc6ae3cc
Reviewed-on: https://review.coreboot.org/c/coreboot/+/59571
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Yu-Ping Wu <yupingso@google.com>

src/mainboard/google/corsola/Kconfig

@@ -30,4 +30,8 @@ config MAINBOARD_PART_NUMBER
 config BOOT_DEVICE_SPI_FLASH_BUS
 	int
 	default 7
+
+config SDCARD_INIT
+	bool
+	default n
 endif

src/mainboard/google/corsola/mainboard.c

@@ -9,7 +9,12 @@
 static void mainboard_init(struct device *dev)
 {
 	mtk_msdc_configure_emmc(true);
+
+	if (CONFIG(SDCARD_INIT)) {
+		printk(BIOS_INFO, "SD card init\n");
 		mtk_msdc_configure_sdcard();
+	}
+
 	setup_usb_host();
 
 	if (spm_init())