powerpc/85xx: Support for Freescale P1024/P1025 processor

Add Support for Freescale P1024/P1025 (dual core) and
P1015/P1016 (single core) processors.

P1024 is a variant of P1020 processor with a core frequency from
400Mhz to 667Mhz and comes in a 561-pin wirebond power-BGA

P1025 is a variant of P1021 processor with a core frequency from
400Mhz to 667Mhz and comes in a 561-pin wirebond power-BGA

P1015 is a variant of P1024 processor with single core and P1016 is a
variant of P1025 processor with single core.

Added comments in config_mpc85xx.h to denote single core versions of
processors.

Signed-off-by: Jin Qing <b24347@freescale.com>
Signed-off-by: Li Yang <leoli@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>