ARM64: zynqmp: Setup correct COUNTER_FREQUENCY for silicon

When U-Boot runs from EL3 system timer is setup based on this macro.
Software default freq for silicon is 100MHz but enable opton to rewrite
it. Emulation platform is using 4MHz.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>

include/configs/xilinx_zynqmp.h

@@ -43,7 +43,9 @@
 #define CONFIG_OF_LIBFDT
 
 /* Generic Timer Definitions - setup in EL3. Setup by ATF for other cases */
-#define COUNTER_FREQUENCY		4000000
+#if !defined(COUNTER_FREQUENCY)
+# define COUNTER_FREQUENCY		100000000
+#endif
 
 /* Size of malloc() pool */
 #define CONFIG_SYS_MALLOC_LEN		(CONFIG_ENV_SIZE + 0x2000000)

include/configs/xilinx_zynqmp_ep.h

@@ -28,6 +28,8 @@
 #define CONFIG_SYS_SDRAM_BASE		0
 #define CONFIG_SYS_SDRAM_SIZE		0x40000000
 
+#define COUNTER_FREQUENCY	4000000
+
 #include <configs/xilinx_zynqmp.h>
 
 #endif /* __CONFIG_ZYNQMP_EP_H */