ARM: OMAP: DRA7: PRCM: Add DRA7XX local MPU PRCM regsiters

Add the PRCM MPU registers for DRA7XX platforms

Signed-off-by: Ambresh K <ambresh@ti.com>
Signed-off-by: Tero Kristo <t-kristo@ti.com>
Signed-off-by: Rajendra Nayak <rnayak@ti.com>
[paul@pwsan.com: added generation notation to comments]
Signed-off-by: Paul Walmsley <paul@pwsan.com>