UPSTREAM: arm64/efi: move virtmap init to early initcall

Now that the create_mapping() code in mm/mmu.c is able to support
setting up kernel page tables at initcall time, we can move the whole
virtmap creation to arm64_enable_runtime_services() instead of having
a distinct stage during early boot. This also allows us to drop the
arm64-specific EFI_VIRTMAP flag.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Bug: 31432001
Change-Id: I57d344d55c5425bdf413116f7c3a1fd51d4e1b59
(cherry picked from commit 60305db9884515ca063474e262b454f6da04e4e2)
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>