net: pch_gbe: Make 64 bit safe

net: pch_gbe: Make 64 bit safe

The pch_gbe driver previously casted pointers to & from unsigned 32 bit
integers in many locations. This breaks the driver on 64 bit systems,
producing streams of compiler warnings about mismatched pointer &
integer sizes and then failing to keep track of addresses correctly at
runtime.

Fix the driver for 64 bit systems by using unsigned longs in place of
the previously used 32 bit integers.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>