uboot-imx

x86: Add generic EFI payload support

It is possible to create a generic EFI payload for all x86 boards.
The payload is configured to include as many generic drivers as
possible. All stuff that touches low-level initialization are not
allowed as such is the EFI BIOS's responsibility. Platform specific
drivers (like gpio, spi, etc) are not included.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>