[ARM] 2978/1: nwfpe - clean up sparse errors

Patch from Ben Dooks

The NWFPE is producing a number of errors from sparse
due to not defining a number of functions in the
header files.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>