[Utopic] [PULL] UBUNTU: fix no console in case of cloud environment V1

[Ming Lei]

Hi Guys,

In current arm64 utopic cloud image, the 'console=' parameter
has been removed from grub config, and always resort to 'stdout'
DT property which is setup from QEMU.

Unfortunately parsing 'stdout' DT property is just merged to 3.19
kernel, so there is no console usable any more for arm64 utopic
VM when booting via uefi/grub.

5 of these 6 patches are cherry picked from 3.19 to utopic, and the
other one is backported by just dropping the dt self-test code, and
with these 6 patches, arm64 utopic VM can be booted with console
usable via uefi/grub.

BugLink: http://bugs.launchpad.net/bugs/1438585

SRU Justification:
    Impact: no console if arm64 utopic based VM is booted from the cloud image
    Fix: backport stdout enablement patches from 3.19
    Testcase: boot one arm64 utopic VM via uefi/grub

So please pull the top 6 patches from below tree/branch:

     git://kernel.ubuntu.com/git/ming/ubuntu-utopic.git  console-fix_stdout

5ba2ee8 of: support passing console options with stdout-path
5c64126 of: add optional options parameter to of_find_node_by_path()
7507839 of: Add bindings for chosen node, stdout-path
54e15d7 of: correct of_console_check()'s return value
4f2b1f0 of: Enable console on serial ports specified by /chosen/stdout-path
a699dfd of: Create of_console_check() for selecting a console
specified in /chosen

V1:
   - fix commit log style
   - add more bug description

Thanks,
Ming Lei