drivers: reset: STi SoC system configuration reset controller support

This patch adds a reset controller implementation for STMicroelectronics
STi family SoCs; it allows a group of related reset like controls found
in multiple system configuration registers to be represented by a single
controller device. System configuration registers are accessed through
the regmap framework and the mfd/syscon driver.

The implementation optionally supports waiting for the reset action to
be acknowledged in a separate status register and supports both
active high and active low reset lines. These properties are common across
all the reset channels in a specific reset controller instance, hence
all channels in a paritcular controller are expected to behave in the
same way.

Signed-off-by: Stephen Gallimore <stephen.gallimore@st.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@st.com>
Acked-by: Philipp Zabel <p.zabel@pengutronix.de>
diff --git a/drivers/reset/sti/Makefile b/drivers/reset/sti/Makefile
new file mode 100644
index 0000000..c4a51d9
--- /dev/null
+++ b/drivers/reset/sti/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_STI_RESET_SYSCFG) += reset-syscfg.o