MCDE: V-sync on main and sub display using DSI BTA

* V-sync support for both primary and secondary display.
* V-sync is disabled by default. It is enabled in menuconfig
  (System Type -> Display selection -> Enable v-sync for
  primary / secondary display).
* DSI HS clock is set to 840 MHz, DSI esq clock 19.2 MHz.
* Enables VAUX1 if startup graphics is enabled.

ST Ericsson Change-Id: WP264234

Reviewed-on: http://gerrit.lud.stericsson.com/gerrit/2154
Tested-by: Dan JOHANSSON <dan.johansson@stericsson.com>
Reviewed-by: Jonas ABERG <jonas.aberg@stericsson.com>
Signed-off-by: Mian Yousaf Kaukab <mian.yousaf.kaukab@stericsson.com>
Change-Id: I47f72cb9449e08f089f6bdb25988bd9958644899
Reviewed-on: http://gerrit.lud.stericsson.com/gerrit/2809
11 files changed