mb/google/corsola: Add MediaTek MT8186 reference board

Add mainboard folder and drivers for new reference board 'Corsola'.

TEST=build pass
BUG=b:200134633

Signed-off-by: Rex-BC Chen <rex-bc.chen@mediatek.com>
Change-Id: I2d701c03c97d3253effb6e93a2d55dcf6cf02db6
Reviewed-on: https://review.coreboot.org/c/coreboot/+/58648
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Rex-BC Chen <rex-bc.chen@mediatek.corp-partner.google.com>
Reviewed-by: Yu-Ping Wu <yupingso@google.com>
diff --git a/src/mainboard/google/corsola/Kconfig b/src/mainboard/google/corsola/Kconfig
new file mode 100644
index 0000000..8b38d2b
--- /dev/null
+++ b/src/mainboard/google/corsola/Kconfig
@@ -0,0 +1,25 @@
+## SPDX-License-Identifier: GPL-2.0-only
+
+# Umbrella option to be selected by variant boards.
+config BOARD_GOOGLE_CORSOLA_COMMON
+	def_bool n
+
+if BOARD_GOOGLE_CORSOLA_COMMON
+
+config BOARD_SPECIFIC_OPTIONS
+	def_bool y
+	select SOC_MEDIATEK_MT8186
+	select BOARD_ROMSIZE_KB_8192
+	select MAINBOARD_HAS_CHROMEOS
+	select COMMON_CBFS_SPI_WRAPPER
+	select SPI_FLASH
+	select SPI_FLASH_INCLUDE_ALL_DRIVERS
+
+config MAINBOARD_DIR
+	string
+	default "google/corsola"
+
+config MAINBOARD_PART_NUMBER
+	string
+	default "Corsola" if BOARD_GOOGLE_CORSOLA
+endif