AMCC PPC 460SX redwood SoC platform initial framework

This patch contains initial framework for the AMCC Redwood board.

Signed-off-by: Madhulika Madishetty <mmadishetty@amcc.com>
Signed-off-by: Tirumala Marri <tmarri@amcc.com>
Signed-off-by: Feng Kan <fkan@amcc.com>
Signed-off-by: Vidhyananth Venkatasamy <vvenkatasamy@amcc.com>
Signed-off-by: Preetesh Parekh <pparekh@amcc.com>
Acked-by: Loc Ho <lho@amcc.com>
Acked-by: Feng Kan <fkan@amcc.com>
Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>