Build fbcmap_mi.c once, rather than once for each DDX, and make it part of libfb
or libwfb convenience library.
Since 84e8de1271 we don't have fbcmap.c
This is a sort of revert of 17d85387d1
v2: Remove libkdrivestubs.la from configure.ac
Signed-off-by: Jon TURNEY <jon.turney@dronecode.org.uk>
Reviewed-by: Gaetan Nadon <memsize@videotron.ca>