parisc: Define depi_safe macro

The depi instruction is similar to the extru instruction on 64-bit machines.
It leaves the most-significant 32 bits of the target register in an undefined
state.  On 64-bit machines, the macro uses depdi to perform safe deposits in
the least-significant 32 bits.

Signed-off-by: John David Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>