idpf: avoid mailbox timeout delays during reset

Mailbox operations are not possible while the driver is in reset.
Operations that require MBX exchange with the control plane will result
in long delays if executed while a reset is in progress:

ethtool -L <inf> combined 8& echo 1 > /sys/class/net/<inf>/device/reset
idpf 0000:83:00.0: HW reset detected
idpf 0000:83:00.0: Device HW Reset initiated
idpf 0000:83:00.0: Transaction timed-out (op:504 cookie:be00 vc_op:504 salt:be timeout:2000ms)
idpf 0000:83:00.0: Transaction timed-out (op:508 cookie:bf00 vc_op:508 salt:bf timeout:2000ms)
idpf 0000:83:00.0: Transaction timed-out (op:512 cookie:c000 vc_op:512 salt:c0 timeout:2000ms)
idpf 0000:83:00.0: Transaction timed-out (op:510 cookie:c100 vc_op:510 salt:c1 timeout:2000ms)
idpf 0000:83:00.0: Transaction timed-out (op:509 cookie:c200 vc_op:509 salt:c2 timeout:60000ms)
idpf 0000:83:00.0: Transaction timed-out (op:509 cookie:c300 vc_op:509 salt:c3 timeout:60000ms)
idpf 0000:83:00.0: Transaction timed-out (op:505 cookie:c400 vc_op:505 salt:c4 timeout:60000ms)
idpf 0000:83:00.0: Failed to configure queues for vport 0, -62

Disable mailbox communication in case of a reset, unless it's done during
a driver load, where the virtchnl operations are needed to configure the
device.

Fixes: 8077c727 ("idpf: add controlq init and reset checks")
Co-developed-by: Joshua Hay <joshua.a.hay@intel.com>
Signed-off-by: Joshua Hay <joshua.a.hay@intel.com>
Signed-off-by: Emil Tantilov <emil.s.tantilov@intel.com>
Reviewed-by: Ahmed Zaki <ahmed.zaki@intel.com>
Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Tested-by: Samuel Salin <Samuel.salin@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>