x86: Move VGA option rom macros to Kconfig

Move X86_OPTION_ROM_FILE & X86_OPTION_ROM_ADDR to arch/x86/Kconfig
and rename them to VGA_BIOS_FILE & VGA_BIOS_ADDR which depend on
HAVE_VGA_BIOS. The new names are consistent with other x86 binary
blob options like HAVE_FSP/FSP_FILE/FSP_ADDR.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>
diff --git a/configs/chromebook_link_defconfig b/configs/chromebook_link_defconfig
index 018fe91..9931d65 100644
--- a/configs/chromebook_link_defconfig
+++ b/configs/chromebook_link_defconfig
@@ -3,6 +3,7 @@
 CONFIG_DEFAULT_DEVICE_TREE="chromebook_link"
 CONFIG_TARGET_CHROMEBOOK_LINK=y
 CONFIG_HAVE_MRC=y
+CONFIG_HAVE_VGA_BIOS=y
 # CONFIG_CMD_IMLS is not set
 # CONFIG_CMD_FLASH is not set
 # CONFIG_CMD_SETEXPR is not set