msm: camera: flash: Apply flash packets at epoch instead of eof

Partial lighted frame can be observed if flash packet is getting applied
at  eof instead of epoch. This change make the flash packet to be
applied at epoch instead of eof.

CRs-Fixed: 2853936
Change-Id: I77dac7c0b8cb8149f26c5f89cced590bc3b957ee
Signed-off-by: Tony Lijo Jose <tjose@codeaurora.org>