spi: add spi-mem driver for MediaTek MT7629 SoC

This patch adds spi-mem driver for MediaTek MT7629 SoC
to access SPI-NOR and SPI-NAND flashes.

[jagan: squash MAINTAINERS file]
Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
Reviewed-by: Jagan Teki <jagan@amarulasolutions.com>
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 2ee0ac9..b9f0327 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -166,6 +166,15 @@
 	  used to access the SPI NOR flash on platforms embedding this
 	  Mediatek QSPI IP core.
 
+config MTK_SNFI_SPI
+	bool "Mediatek SPI memory controller driver"
+	depends on SPI_MEM
+	help
+	  Enable the Mediatek SPI memory controller driver. This driver is
+	  originally based on the MediaTek SNFI IP core. It can only be
+	  used to access SPI memory devices like SPI-NOR or SPI-NAND on
+	  platforms embedding this IP core, like MT7622/M7629.
+
 config MVEBU_A3700_SPI
 	bool "Marvell Armada 3700 SPI driver"
 	select CLK_ARMADA_3720