Update the current QEMU installation script with option to override QEMU
installation and to apply additional patches. Additional patches are
applied from qemu_patches directory and subdir for specific QEMU version by
run-parts. This means that all patches for particular version are
applied.
All keywords for build QEMU are updated.
Change-Id: I0c874a96ac828dff657ee33eb87d88a8854128ad
Signed-off-by: pmikus <pmikus@cisco.com>