Summary: enable activation of southern islands radeon cards without blobs

Summary: enable activation of southern islands radeon cards without blobs

The si.c file also needed to be patched to avoid the following probe
failure due to the missing MC firmrware:
  [drm:si_startup [radeon]] *ERROR* Failed to load MC firmware!
  radeon 0000:02:00.0: disabling GPU acceleration
  radeon 0000:02:00.0: 00000000b8c27aec unpin not necessary
  [drm:si_init [radeon]] *ERROR* radeon: MC ucode required for NI+.
  radeon 0000:02:00.0: Fatal error during GPU init
  [...]
  radeon: probe of 0000:02:00.0 failed with error -22

This has been tested with the following GPU:
  02:00.0 VGA compatible controller: Advanced Micro Devices, Inc.
  [AMD/ATI] Cape Verde PRO [Radeon HD 7750/8740 / R7 250E] [1002:683f]

Xorg, lightdm, xfce4, mplayer and wesnoth have been tested and work
fine, though in mplayer the OSD has some light artefacts.

Signed-off-by: Denis 'GNUtoo' Carikli <GNUtoo@no-log.org>
git-svn-id: http://www.fsfla.org/svn/fsfla/software/linux-libre/scripts@17089 559672b5-ba27-0410-b829-e8f1faed8b1b