iwlwifi: mvm: skip power command when unbinding vif during CSA

In the new CSA flow, we remain associated during CSA, but
still do a unbind-bind to the vif. However, sending the power
command right after when vif is unbound but still associated
causes FW to assert (0x3400) since it cannot tell the LMAC id.

Just skip this command, we will send it again in a bit, when
assigning the new context.

Signed-off-by: Sara Sharon <sara.sharon@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/iwlwifi.20210115130252.64a2254ac5c3.Iaa3a9050bf3d7c9cd5beaf561e932e6defc12ec3@changeid