uio_pdrv_genirq: Allow use with non-page-aligned memory resources

uio_pdrv_genirq: Allow use with non-page-aligned memory resources

Similar to the changes made in 270579d95f82 ("uio_mf624: Align memory
regions to page size and set correct offsets"), this will allow
uio_pdrv_genirq devices to expose memory regions that is not page-aligned,
requiring the users to respect the offset sysfs attribute (as implemented
in libuio).

Signed-off-by: Esben Haabendal <esben@geanix.com>
Link: https://lore.kernel.org/r/20200701145659.3978-4-esben@geanix.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>