thermal/drivers/imx: Fix a build error: 'run_measurement' undeclared in imx_get_temp

Refer to Upstream commit 4cf2ddf1("thermal/drivers/imx:
Implement runtime PM support"), run_measurement has been
deleted, this is a conflict generated during merge commit
c5b25bdc

Signed-off-by: Xiaolei Wang <xiaolei.wang@windriver.com>
Signed-off-by: Bruce Ashfield <bruce.ashfield@gmail.com>