media: i2c: dw9768: use pm_runtime_resume_and_get()

Commit dd8088d5 ("PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter")
added pm_runtime_resume_and_get() in order to automatically handle
dev->power.usage_count decrement on errors.

Use the new API, in order to cleanup the error check logic.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>