w100fb: do not depend on SHARPSL

Apart from Sharp SL-Cxx series, there are a few other devices that have
ATI Imageon chips, among them HP iPAQ hx4700.

Signed-off-by: Philipp Zabel <philipp.zabel@gmail.com>
Acked-by: Ian Molton <spyro@f2s.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>