parisc/unaligned: Fix ldw() and stw() unalignment handlers

Fix 3 bugs:

a) emulate_stw() doesn't return the error code value, so faulting
instructions are not reported and aborted.

b) Tell emulate_ldw() to handle fldw_l as floating point instruction

c) Tell emulate_ldw() to handle ldw_m as integer instruction

Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org