mt76: mt76x0u: do not reset radio on resume

On some machines mt76x0u firmware can hung during resume,
what result on messages like below:

[  475.480062] mt76x0 1-8:1.0: Error: MCU response pre-completed!
[  475.990066] mt76x0 1-8:1.0: Error: send MCU cmd failed:-110
[  475.990075] mt76x0 1-8:1.0: Error: MCU response pre-completed!
[  476.500003] mt76x0 1-8:1.0: Error: send MCU cmd failed:-110
[  476.500012] mt76x0 1-8:1.0: Error: MCU response pre-completed!
[  477.010046] mt76x0 1-8:1.0: Error: send MCU cmd failed:-110
[  477.010055] mt76x0 1-8:1.0: Error: MCU response pre-completed!
[  477.529997] mt76x0 1-8:1.0: Error: send MCU cmd failed:-110
[  477.530006] mt76x0 1-8:1.0: Error: MCU response pre-completed!
[  477.824907] mt76x0 1-8:1.0: Error: send MCU cmd failed:-71
[  477.824916] mt76x0 1-8:1.0: Error: MCU response pre-completed!
[  477.825029] usb 1-8: USB disconnect, device number 6

and possible whole system freeze.

This can be avoided, if we do not perform mt76x0_chip_onoff() reset.

Cc: stable@vger.kernel.org
Fixes: 134b2d0d

 ("mt76x0: init files")
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>