msm: vidc: Fix unsupported codec error from video driver

- Client is getting unsupported codec error for set format
  sometimes after opening the video driver because driver
  was not updated with supported codecs information from
  video hardware.
- The same issue can be fixed by waiting for the driver state
  changed to CORE_INIT_DONE, which ensures the supported codecs
  information will be updated in video driver, before checking
  the supported codecs information.

CRs-fixed: 590158
Change-Id: Ia9132fdc01e4fa53533a3c9d14069d49501fa7d7
Signed-off-by: Maheshwar Ajja <majja@codeaurora.org>