staging: vc04_services: Remove function block_resume()

Remove function block_resume as it was only called by
vchiq_arm_force_suspend, which was removed in a previous patch.
Issue found with Coccinelle.

Signed-off-by: Nishka Dasgupta <nishkadg.linux@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>