cryptsetup: add support for workqueue options

cryptsetup: add support for workqueue options

This commit adds support for disabling the read and write
workqueues with the new crypttab options no-read-workqueue
and no-write-workqueue. These correspond to the cryptsetup
options --perf-no_read_workqueue and --perf-no_write_workqueue
respectively.

(cherry picked from commit 227acf0009bde2cd7f8bc371615b05e84137847d)