x86/efi: Remove the unused efi_get_time() function

Nothing calls the efi_get_time() function on x86, but it does suffer
from the 32-bit time_t overflow in 2038.

This removes the function, we can always put it back in case we need
it later.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1466839230-12781-8-git-send-email-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>