nvme: Export get and set features

nvme: Export get and set features

BugLink: https://bugs.launchpad.net/bugs/1808957
Future use intends to make use of both, so export these functions. And
since their implementation is identical except for the opcode, provide a
new function that implement both.

[akinobu.mita@gmail.com>: fix line over 80 characters]
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Minwoo Im <minwoo.im.dev@gmail.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
(backported from commit 82b17aebf68d572d73359a68376024ec1b5294c5 git://git.infradead.org/nvme nvme-5.3)
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Acked-by: Timo Aaltonen <tjaalton@ubuntu.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>