iwlwifi: pcie: remove obsolete pre-release support code

We no longer need code that was introduced to differentiate
between two early versions of 8260.

We can remove this convoluted way to get the hardware version
that was needed because of a bug in the register's
configuration.

Moreover, since we no longer need to access the PRPH
registers, we no longer need to wake up the device,
request ownership, etc...
Remove all that.

This allows us to get the rid of the obsolete comment
about the AUX bus MISC address space which should have
been moved when this code was moved away from here.

Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20201209231352.4a5665ccd8a6.Iff3879405c15758ba661c430e77dc2160ddada1c@changeid


Signed-off-by: Luca Coelho <luciano.coelho@intel.com>