rng: Add StarFive JH7110 RNG driver

Adds to support JH7110 TRNG driver which is based on linux kernel's
jh7110-trng.c. This can support to generate 256-bit random numbers and
128-bit but this makes 256-bit default for convenience.

Signed-off-by: Chanho Park <chanho61.park@samsung.com>
Reviewed-by: Leo Yu-Chi Liang <ycliang@andestech.com>
diff --git a/drivers/rng/Kconfig b/drivers/rng/Kconfig
index 4f6e367..a89c899 100644
--- a/drivers/rng/Kconfig
+++ b/drivers/rng/Kconfig
@@ -99,4 +99,10 @@
 	  functionality. Enable random number generator on TPM
 	  devices.
 
+config RNG_JH7110
+	bool "StarFive JH7110 Random Number Generator support"
+	depends on DM_RNG && STARFIVE_JH7110
+	help
+	  Enable True Random Number Generator in StarFive JH7110 SoCs.
+
 endif