wifi: iwlwifi: move _iwl_trans_set_bits_mask utilities

Move set_bits_mask utility functions to utils.h as they are generic
utilities and is not hardware-dependent.

Signed-off-by: Rotem Kerem <rotem.kerem@intel.com>
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Link: https://patch.msgid.link/20250612144708.4049f1eda9fa.Iddcb6f7437beee2cfe232315384d8517b40c56d1@changeid