drivers: sensor: voltage_divider: fix unchecked pm_device_runtime_get()

Fix Coverity CID 529858 (CWE-252): Previously, the return value of
pm_device_runtime_get() was not checked during PM resume, which could
lead to missed error conditions.

This patch ensures proper error handling by checking and propagating
the return status of the call.

Fixes: #92608

Signed-off-by: sudarsan N <sudarsansamy2002@gmail.com>