staging: wilc1000: fix line over 80 chars in handle_key()

Fix checkpatch reported issue of line over 80 char in handle_key().
Introduced new functions by spliting existing function to address the
checkpatch issue.

Signed-off-by: Ajay Singh <ajay.kathat@microchip.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>