MUSB: Blackfin: remove musb_platform_{suspend|resume}()

These functions do nothing and also are both unnecessarily 'extern'; actually,
musb_platform_resume() in not even called...

Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Felipe Balbi <felipe.balbi@nokia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>