This diff seems larger than it is since upstream reindented some
sources. This updates libdrm_intel to -current (which only affect the
GEM code) and libdrm to 2.4.15. bumping both minor versions.
Discussed with matthieu@
are to some assertions and a small change to modesetting code).
bump libdrm_intel minor due to added symbols, libdrm doesn't get bumped,
no change to symbol list.
ok matthieu@.
