rockchip: reset: support a (common) rockchip reset drivers

Create driver to support the soft reset (i.e. peripheral)
of all Rockchip SoCs.

Example of usage:
i2c driver:
	ret = reset_get_by_name(dev, "i2c", &reset_ctl);
	if (ret) {
		error("reset_get_by_name() failed: %d\n", ret);
	}

	reset_assert(&reset_ctl);
	udelay(50);
	reset_deassert(&reset_ctl);

i2c dts node:
resets = <&cru SRST_P_I2C1>, <&cru SRST_I2C1>;
reset-names = "p_i2c", "i2c";

Signed-off-by: Elaine Zhang <zhangqing@rock-chips.com>
Signed-off-by: Kever Yang <kever.yang@rock-chips.com>
Acked-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Reviewed-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
[Fixed commit tag:]
Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig
index ce46e27..3964b9e 100644
--- a/drivers/reset/Kconfig
+++ b/drivers/reset/Kconfig
@@ -74,4 +74,13 @@
 	  resets that are supported by watchdog. The main limitation though
 	  is that some reset signals, like I2C or MISC reset multiple devices.
 
+config RESET_ROCKCHIP
+	bool "Reset controller driver for Rockchip SoCs"
+	depends on DM_RESET && ARCH_ROCKCHIP && CLK
+	default y
+	help
+	  Support for reset controller on rockchip SoC. The main limitation
+	  though is that some reset signals, like I2C or MISC reset multiple
+	  devices.
+
 endmenu