Patch from Ian Campbell

Sorry, 1926/2 was missing a brace. Fixed here.

Previous commentry:
I have corrected the grayscale conversion to correctly use the upper
byte rather than the lower one. As requested I have also left the
actual grayscale conversion where it was this time and just dealt with
the palette differences in pxafb_setpalettereg.

fb_alloc_cmap is only called when bits_per_pixel is < 16, otherwise
any existing cmap is freed.

I also fixed up all the spaces and brackets issues (not just the one
you raised previously) this introduces some noise in the patch, if
you'd like the two patches separately please ask.