arm64: Extend the PCI I/O space to 16MB

The patch moves the PCI I/O space (currently at 64K) before the
earlyprintk mapping and extends it to 16MB.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git


Git-commit: 22bd1c91fe13d59cff734b69b6757adcfbd8dee9
[joonwoop@codeaurora.org: fixed trivial merge conflict.  arm64 pcie
 change merged first]
Signed-off-by: Joonwoo Park <joonwoop@codeaurora.org>