MIPS: clean up resume declaration

This patch cleans up the declaration of the resume function by replacing
void pointers with their correct types. The irrelevant & incorrect
comment preceeding the resume function is replaced by one documenting
its function.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Reviewed-by: Qais Yousef <qais.yousef@imgtec.com>
Signed-off-by: John Crispin <blogic@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/6146/