iwlwifi: mvm: always use 4K RB size by default

When we use 2K RBs, we cannot receive all valid 802.11 frames,
including e.g. long beacons, since up to 2304 bytes are valid
(plus metadata and also encryption overhead etc.). Increase
the RB size to be always 4K to avoid that.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20211204174545.675781ab0da5.I5c653f4c7dd726f8ad40077e4a109b85e7c0cdb1@changeid


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