video/macfb: Remove redundant code

The value of info->var.bits_per_pixel get checked in macfb_setcolreg().
Remove additional checks as they are redundant.

macfb_defined.activate gets initialized to FB_ACTIVATE_NOW by the struct
initializer. Remove redundant assignments.

macfb_defined.bits_per_pixel, .width and .height all get assigned
unconditionally. Remove redundant initializers.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Tested-by: Stan Johnson <userm57@yahoo.com>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>