stm32mp1: rng: Add a driver for random number generator(rng) device

Add a driver for the rng device found on stm32mp1 platforms. The
driver provides a routine for reading the random number seed from the
hardware device.

Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
Reviewed-by: Patrice Chotard <patrice.chotard@st.com>
Acked-by: Patrick Delaunay <patrick.delaunay@st.com>
Remove a superfluous blank line
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
diff --git a/drivers/rng/Kconfig b/drivers/rng/Kconfig
index dd44cc0..c9c4751 100644
--- a/drivers/rng/Kconfig
+++ b/drivers/rng/Kconfig
@@ -5,3 +5,10 @@
 	  Enable driver model for random number generator(rng) devices.
 	  This interface is used to initialise the rng device and to
 	  read the random seed from the device.
+
+config RNG_STM32MP1
+	bool "Enable random number generator for STM32MP1"
+	depends on ARCH_STM32MP && DM_RNG
+	default n
+	help
+	  Enable STM32MP1 rng driver.