ASoC: Change platform driver to component driver

snd_soc_platform_driver is removed in kernel-4.19.
Update snd_soc_platform_driver to snd_soc_component_driver.

Change-Id: I434b6fd173d1f4365a610d9164342d5d04d6c5bc
Signed-off-by: Meng Wang <mengw@codeaurora.org>