msm: camera: isp: Switching between rdi and pix rup for fs2 state machine

Preview state machine should transitions states from APPLIED to EPOCH
on PIX RUP. It is wrongly doing on RDI RUP. For preview request PIX RUP
is used to confirm for successful apply done. In snapshot request, RDI RUP
is used for successful apply.
This change selects between RDI RUP and PIX RUP  based on request packet.

Change-Id: Iab4f84061e78e3327c2e22154a146ef86280b896
Signed-off-by: Alok Pandey <akumarpa@codeaurora.org>