FROMLIST: nvme: zns: Allow ZNS drives that have non-power_of_2 zone size

Remove the condition which disallows non-power_of_2 zone size ZNS drive
to be updated and use generic method to calculate number of zones
instead of relying on log and shift based calculation on zone size.

The power_of_2 calculation has been replaced directly with generic
calculation without special handling. Both modified functions are not
used in hot paths, they are only used during initialization &
revalidation of the ZNS device.

As rounddown macro from math.h does not work for 32 bit architectures,
round down operation is open coded.

Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed by: Adam Manzanares <a.manzanares@samsung.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: Pankaj Raghav <p.raghav@samsung.com>
Bug: 197782466
Bug: 269471019
Link: https://lore.kernel.org/linux-block/20220923173618.6899-6-p.raghav@samsung.com/


Change-Id: Id15b9b6f68498477f3d1c6159c5a459749f856a9
Signed-off-by: Bart Van Assche <bvanassche@google.com>