Convert CONFIG_SYS_OMAP_ABE_SYSCK to Kconfig

This converts the following to Kconfig:
   CONFIG_SYS_OMAP_ABE_SYSCK

Signed-off-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/arm/mach-omap2/omap5/Kconfig b/arch/arm/mach-omap2/omap5/Kconfig
index 4c2f990..18a6676 100644
--- a/arch/arm/mach-omap2/omap5/Kconfig
+++ b/arch/arm/mach-omap2/omap5/Kconfig
@@ -2,6 +2,7 @@
 
 config DRA7XX
 	bool
+	select SYS_OMAP_ABE_SYSCK
 	help
 	  DRA7xx is an OMAP based SOC with Dual Core A-15s.