powerpc/p1010rdb:update dts to adapt to both old and new p1010rdb

P1010rdb-pa and p1010rdb-pb have different phy interrupts.
So update dts to adapt to both p1010rdb-pa and p1010rdb-pb.

Signed-off-by: Shengzhou Liu <Shengzhou.Liu@freescale.com>
Signed-off-by: Zhao Qiang <B45475@freescale.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>