arm: zynq: Enable SPL_CLK only if SPL is enabled

Setup proper dependency in Kconfig for SPL_CLK.
If SPL is not enabled, SPL_CLK shouldn't be selected.

Cc: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>

arch/arm/Kconfig

@@ -790,7 +790,7 @@ config ARCH_ZYNQ
 	select DM_USB if USB
 	select BLK
 	select CLK
-	select SPL_CLK
+	select SPL_CLK if SPL
 	select CLK_ZYNQ
 	imply CMD_CLK
 	imply FAT_WRITE