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: NSergio Aguirre <saaguirre@ti.com>
Signed-off-by: NGovindraj.R <govindraj.raja@ti.com>
Acked-by: NPaul Walmsley <paul@pwsan.com>
Signed-off-by: NKevin Hilman <khilman@deeprootsystems.com>