powerpc/85xx: Added P1020RDB Platform support.

P1020 is another member of Freescale QorIQ series of processors.
It is an e500 based dual core SOC.
Being a scaled down version of P2020 it has following differences from P2020:
- 533MHz - 800MHz core frequency.
- 256Kbyte L2 cache
- Ethernet controllers with classification capabilities(new controller).

From board perspective P1020RDB is same as P2020RDB.

Signed-off-by: Poonam Aggrwal <poonam.aggrwal@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>