uboot-phytec

efi_loader: add RuntimeServicesSupported variable

This variable is defined in UEFI specification 2.8, section 8.1.
Its value should be updated whenever we add any usable runtime services
function.

Currently we only support SetVirtualAddress() for all systems and
ResetSystem() for some.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>