timer: starfive: Add Starfive timer support

Add timer driver in Starfive SoC. It is an timer that outside
of CPU core and inside Starfive SoC.

Signed-off-by: Kuan Lim Lee <kuanlim.lee@starfivetech.com>
Reviewed-by: Wei Liang Lim <weiliang.lim@starfivetech.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/timer/Kconfig b/drivers/timer/Kconfig
index 915b2af..a98be9d 100644
--- a/drivers/timer/Kconfig
+++ b/drivers/timer/Kconfig
@@ -326,4 +326,11 @@
 	  Select this to enable support for the timer found on
 	  any Xilinx boards (axi timer).
 
+config STARFIVE_TIMER
+	bool "Starfive timer support"
+	depends on TIMER
+	help
+	  Select this to enable support for the timer found on
+	  Starfive SoC.
+
 endmenu