iio: imu: kmx61: Balance runtime pm + use pm_runtime_resume_and_get()

No point in calling pm_runtime_put_noidle() that isn't balancing a get.
Note no actual impact because the runtime pm core protects against
a negative reference counter.

For the pm_runtime_resume_and_get() main interest is in clearing
out this old pattern to avoid it getting coppied into new submissions.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/20210509113354.660190-10-jic23@kernel.org