roms: remove option rom packing logic

roms: remove option rom packing logic

Now that we load the option roms via fw_cfg, we can stop copying
them to the 0xc000 -> 0xe000.  The patch does just that.

Also the rom loader gets simplified as all remaining users of the
rom loader load the bits at a fixed address so the packing and
aligning logic can go away.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
(cherry picked from commit 632cf034b401cdd01dae253a8b577fe518e37654)