camera: Fix loss of focus mode between shots

exynos_camera->focus_mode can't be relied upon to verify the previous
state, since a snapshot will reset the focus state. This was causing
any mode besides auto-focus (enum 0) to fail after the first photo
was taken, including the default continuous-picture.

Always make sure the focus-mode is up to date when set_params is
called

(Submitted to CM repos by rmcc outside of CM Gerrit)

Change-Id: Iac8f2f21d63ba198fd57cdf567032f2f5b0da0fb