iwlwifi: move ucode_type from shared to op_mode

This variable holds the ucode currently
running on the device; which is determined by
op_mode, so move this parameter there.

Also, the name of the variable is a bit
misleading, so rename it to cur_ucode.

Signed-off-by: Meenakshi Venkataraman <meenakshi.venkataraman@intel.com>
Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>