ARM64: zynqmp: Use the same U-Boot version with/without ATF

Remove SECURE_IOU option which is not needed. U-Boot itself can detect
which EL level it is on and based on that use do platform setup.
It also simplify usage because one Kconfig entry is gone.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
diff --git a/arch/arm/cpu/armv8/zynqmp/clk.c b/arch/arm/cpu/armv8/zynqmp/clk.c
index 9218586..40bd2ca 100644
--- a/arch/arm/cpu/armv8/zynqmp/clk.c
+++ b/arch/arm/cpu/armv8/zynqmp/clk.c
@@ -26,6 +26,22 @@
 	return 133000000;
 }
 
+unsigned long zynqmp_get_system_timer_freq(void)
+{
+	u32 ver = zynqmp_get_silicon_version();
+
+	switch (ver) {
+	case ZYNQMP_CSU_VERSION_VELOCE:
+		return 10000;
+	case ZYNQMP_CSU_VERSION_EP108:
+		return 4000000;
+	case ZYNQMP_CSU_VERSION_QEMU:
+		return 50000000;
+	}
+
+	return 100000000;
+}
+
 #ifdef CONFIG_CLOCKS
 /**
  * set_cpu_clk_info() - Initialize clock framework