iwlwifi: BZ Family BUS_MASTER_DISABLE_REQ code duplication

Remove redundant code which occurs anyway in a later stage and add
msleep(100) which is required after disable request.

Signed-off-by: Roee Goldfiner <roee.h.goldfiner@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20211017162352.46183bcd6549.Ie05161496810d3f28fb9d1fecb5f8593889ed2c6@changeid


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