Convert CONFIG_CLOCKS to Kconfig

This converts the following to Kconfig:
   CONFIG_CLOCKS

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/xilinx_zynqmp_mini_defconfig b/configs/xilinx_zynqmp_mini_defconfig
index d96f1b3..86e862d 100644
--- a/configs/xilinx_zynqmp_mini_defconfig
+++ b/configs/xilinx_zynqmp_mini_defconfig
@@ -17,6 +17,7 @@
 # CONFIG_AUTOBOOT is not set
 # CONFIG_DISPLAY_CPUINFO is not set
 # CONFIG_BOARD_LATE_INIT is not set
+CONFIG_CLOCKS=y
 # CONFIG_CMDLINE_EDITING is not set
 # CONFIG_AUTO_COMPLETE is not set
 # CONFIG_SYS_LONGHELP is not set