OMAP3: PRCM: Consider UART4 for 3630 chip in prcm_setup_regs

To standarize among other uarts (1 to 3), we shall now:

 - Enable uart4 autodile bit.
 - Enable uart4 wakeup in PER.
 - Allow uart4 to wakeup the MPU.

Signed-off-by: Sergio Aguirre <saaguirre@ti.com>
Signed-off-by: Govindraj.R <govindraj.raja@ti.com>
Acked-by: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>