Staging: vme: Pull common VME interrupt handling into core code

Currently the VME callback infrastructure is replicated in each VME driver.
Move this common code into the VME core. Rename functions to fit in better
with naming of other VME functions.

Signed-off-by: Martyn Welch <martyn.welch@gefanuc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>