spi: add support for MediaTek spi-mem controller

This patch adds support for spi-mem controller found on newer MediaTek SoCs
This controller supports Single/Dual/Quad SPI mode.

Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Daniel Golle <daniel@makrotopia.org>
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index 7ba953d..50ba435 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -44,6 +44,7 @@
 obj-$(CONFIG_MPC8XXX_SPI) += mpc8xxx_spi.o
 obj-$(CONFIG_MTK_SNFI_SPI) += mtk_snfi_spi.o
 obj-$(CONFIG_MTK_SNOR) += mtk_snor.o
+obj-$(CONFIG_MTK_SPIM) += mtk_spim.o
 obj-$(CONFIG_MT7620_SPI) += mt7620_spi.o
 obj-$(CONFIG_MT7621_SPI) += mt7621_spi.o
 obj-$(CONFIG_MSCC_BB_SPI) += mscc_bb_spi.o