efi: Remove global 'memmap' EFI memory map

Abolish the poorly named EFI memory map, 'memmap'. It is shadowed by a
bunch of local definitions in various files and having two ways to
access the EFI memory map ('efi.memmap' vs. 'memmap') is rather
confusing.

Furthermore, IA64 doesn't even provide this global object, which has
caused issues when trying to write generic EFI memmap code.

Replace all occurrences with efi.memmap, and convert the remaining
iterator code to use for_each_efi_mem_desc().

Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Luck, Tony <tony.luck@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1461614832-17633-8-git-send-email-matt@codeblueprint.co.uk


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