atomisp: set the digital zoom in atomisp_set_fmt()

atomisp: set the digital zoom in atomisp_set_fmt()

BZ: 43056

Zoom must be recalculated by calling atomisp_digital_zoom()
when switching resolution.

Originally from: Zhi Jin <zhi.jin@intel.com>
Change-Id: Idbf5568965cb1ff20e0b255f269b627b4afbc2b3
Signed-off-by: Tuukka Toivonen <tuukka.toivonen@intel.com>
Reviewed-on: http://android.intel.com:8080/53557
Reviewed-by: Kontola, Kalervo <kalervo.kontola@intel.com>
Reviewed-by: Tuominen, TeemuX <teemux.tuominen@intel.com>
Reviewed-by: Koski, Anttu <anttu.koski@intel.com>
Tested-by: Koski, Anttu <anttu.koski@intel.com>
Reviewed-by: buildbot <buildbot@intel.com>
Tested-by: buildbot <buildbot@intel.com>