dm-integrity: support recalculation in the 'I' mode

In the kernel 6.11, dm-integrity was enhanced with an inline ('I') mode.
This mode uses devices with non-power-of-2 sector size. The extra
metadata after each sector are used to hold the integrity hash.

This commit enhances the inline mode, so that there is automatic
recalculation of the integrity hashes when the 'reclaculate' parameter is
used. It allows us to activate the device instantly, and the
recalculation is done on background.

If the device is deactivated while recalculation is in progress, it will
remember the point where it stopped and it will continue from this point
when activated again.

Signed-off-by: Mikulas Patocka <[email protected]>

Author: Mikulas Patocka