ARM64: zynqmp: Enable CLK and SPL_CLK by default

Serial driver starts to use clk framework that's why
enable it by default.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 585b408..397981a 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -669,6 +669,8 @@
 	select OF_CONTROL
 	select DM_SERIAL
 	select SUPPORT_SPL
+	select CLK
+	select SPL_CLK
 
 config TEGRA
 	bool "NVIDIA Tegra"