Convert CONFIG_SPL_BOARD_INIT to Kconfig

This converts the following to Kconfig:
   CONFIG_SPL_BOARD_INIT

Signed-off-by: Ley Foon Tan <ley.foon.tan@intel.com>
[trini: Update the Kconfig logic]
Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/arch/arm/mach-socfpga/Kconfig b/arch/arm/mach-socfpga/Kconfig
index 2563e79..45e5379 100644
--- a/arch/arm/mach-socfpga/Kconfig
+++ b/arch/arm/mach-socfpga/Kconfig
@@ -39,6 +39,7 @@
 
 config TARGET_SOCFPGA_ARRIA10
 	bool
+	select SPL_BOARD_INIT if SPL
 
 config TARGET_SOCFPGA_CYCLONE5
 	bool