Fix the code to fetch and decode the whole 32-bit instruction.  This
only really matters with the `noulri' kernel parameter as all microMIPS
processors are supposed to have all the hardware registers we support.
Signed-off-by: NMaciej W. Rozycki <macro@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/12281/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>