[PATCH] fbcmap.c: mark structs const or __read_mostly

- Mark the default colormaps read-only, as nobody should be allowed to
  modify them

- Additionally mark color values as __read_mostly since they will only be
  modified (very seldom) by fb_invert_cmaps()

- Add named C99-initializers in fb_cmap structs and use the ARRAY_SIZE()
  macro

Signed-off-by: Helge Deller <deller@gmx.de>
Acked-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>