reset: add reset controller driver for MediaTek MIPS platform

This patch adds reset controller driver for MediaTek MIPS platform and
header file for mt7628.

diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile
index f5875fc..8102d8d 100644
--- a/drivers/reset/Makefile
+++ b/drivers/reset/Makefile
@@ -18,6 +18,7 @@
 obj-$(CONFIG_RESET_MESON) += reset-meson.o
 obj-$(CONFIG_RESET_SOCFPGA) += reset-socfpga.o
 obj-$(CONFIG_RESET_MEDIATEK) += reset-mediatek.o
+obj-$(CONFIG_RESET_MTMIPS) += reset-mtmips.o
 obj-$(CONFIG_RESET_SUNXI) += reset-sunxi.o
 obj-$(CONFIG_RESET_HISILICON) += reset-hisilicon.o
 obj-$(CONFIG_RESET_IMX7) += reset-imx7.o