buildgcc: Update to binutils-2.26.1 & Fix aarch64 build issue

buildgcc: Update to binutils-2.26.1 & Fix aarch64 build issue

- Update to the latest version of GNU binutils
- Add a patch to undo the changes to binutils done by commit c1baaddf
so that arm-trusted-firmware builds correctly again.

Test: Build arm-trusted-firmware (ATF) with this patch.  Build ATF
with binutils 2.26.1 changing the '.align x,0' to '.align x', which
changes the padding bytes to NOP instructions.  Verify that everything
except the padding bytes is the same.

See https://sourceware.org/bugzilla/show_bug.cgi?id=20364 for more
information about this issue.

Change-Id: I559c863c307b4146f8be8ab44b15c9c606555544
Signed-off-by: Martin Roth <martinroth@google.com>
Reviewed-on: https://review.coreboot.org/15711
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
Tested-by: build bot (Jenkins)
Reviewed-by: Furquan Shaikh <furquan@google.com>