xilinx: versal-net: Add support for timer and start it

Add support for starting timer by setting up time stamp generator
registers. This is done only for EL3 i.e. mini U-Boot case.
For other cases, it will be done TF-A.

Add COUNTER_FREQUENCY and IOU_SWITCH_DIVISOR0 to Kconfig so that they
can be tuned as required.

Signed-off-by: Ashok Reddy Soma <ashok.reddy.soma@amd.com>
Signed-off-by: Michal Simek <michal.simek@amd.com>
Link: https://lore.kernel.org/r/fcd8b0dc4b45a11f5e753afff42f84738ac813da.1673336645.git.michal.simek@amd.com
diff --git a/arch/arm/mach-versal-net/Kconfig b/arch/arm/mach-versal-net/Kconfig
index 62825e1..edff5b0 100644
--- a/arch/arm/mach-versal-net/Kconfig
+++ b/arch/arm/mach-versal-net/Kconfig
@@ -21,6 +21,18 @@
 	  Based on this option include/configs/<CONFIG_SYS_CONFIG_NAME>.h header
 	  will be used for board configuration.
 
+config COUNTER_FREQUENCY
+	int "Timer clock frequency"
+	default 0
+	help
+	  Setup time clock frequency for certain platform
+
+config IOU_SWITCH_DIVISOR0
+	hex "IOU switch divisor0"
+	default 0x20
+	help
+	  Setup time clock divisor for input clock.
+
 config SYS_MEM_RSVD_FOR_MMU
 	bool "Reserve memory for MMU Table"
 	help