Instead of using pci_set_drvdata embed the 'struct voicebus_operations'
directly in the context so we can use container_of to find the context.
This resolves a problem where the 'remove_one' callback gets an invalid
pointer to 'struct t1' if the VPMADT032 is in the middle of a reload
when the module is unloading. DAHDI-783.
Signed-off-by: Shaun Ruffell <sruffell@digium.com>
git-svn-id: http://svn.asterisk.org/svn/dahdi/linux/trunk@9554 a0bf4364-ded3-4de4-8d8a-66a801d63aff