staging: android: binder: add enum usage in function arguments

Declare the binder_deferred_state enum, and use the new enum
for one of the binder_defer_work function arguments. This
should keep the argument within the confines of the enum
instead of the whole int range.

Signed-off-by: Daniel Walker <dwalker@fifo99.com>
Cc: Brian Swetland <swetland@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>