UPSTREAM: arm64/efi: drop redundant set_bit(EFI_CONFIG_TABLES)

The EFI_CONFIG_TABLES bit already gets set by efi_config_init(),
so there is no reason to set it again after this function returns
successfully.

Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

(cherry picked from commit 4e27d4754e8990da264c1e01e2f6bd8340e30cb3)
Signed-off-by: Tomasz Figa <tfiga@chromium.org>

Bug: 24475017

Change-Id: I13a64ac2630ec1db22d4d4de4ebe9597cb83e291
Signed-off-by: Kees Cook <keescook@google.com>