x86/efi: Allow invocation of arbitrary runtime services

Provide the ability to perform mixed-mode runtime service calls for x86 in
the same way the following commit provided the ability to invoke for boot
services:

  0a637ee6 ("x86/efi: Allow invocation of arbitrary boot services")

Suggested-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1486380166-31868-2-git-send-email-ard.biesheuvel@linaro.org


Signed-off-by: Ingo Molnar <mingo@kernel.org>