The MPU subsystem was named based on internal code name (CHIRON).
This patch will remove all the occurences of the chiron name
are replace it with PRCM_MPU in order to differentiate
the MPU local PRCM to the global one.

Remove PDA_ from PRCM_MPU registers names to stick to the global
PRM naming convention.
Signed-off-by: Benoit Cousson <b-cousson@ti.com>
Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Rajendra Nayak <rnayak@ti.com>