x86: Introduce USE_EARLY_BOARD_INIT option

Introduce USE_EARLY_BOARD_INIT option and select it by the actual users.

Cc: George McCollister <george.mccollister@gmail.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Stefan Roese <sr@denx.de>
Reviewed-by: Aiden Park <aiden.park@intel.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index a34b108..76276c6 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -203,6 +203,9 @@
 	help
 	  This is enabled when 32-bit init is in SPL
 
+config USE_EARLY_BOARD_INIT
+	bool
+
 config RESET_SEG_START
 	hex
 	depends on X86_RESET_VECTOR