powerpc: Enable Little Endian Alignment Handler for Float Pair Instructions

This patch enables alignment handling for the load/store floating point
pair instructions (lfdp, lfdpx, stfdp, stfdpx).  The handler routine
is properly coded and only needs to be enabled.

Signed-off-by: Tom Musta <tmusta@gmail.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>