thermal/drivers/qcom: Make LMH select QCOM_SCM

The QCOM_SCM symbol is not user-visible, so it makes little sense to
depend on it. Make LMH driver select QCOM_SCM as all other drivers do
and, as the dependecy is now correctly handled, enable || COMPILE_TEST
in order to include the driver into broader set of build tests.

Fixes: 9e5a4fb8 ("thermal/drivers/qcom/lmh: make QCOM_LMH depends on QCOM_SCM")
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20250728-lmh-scm-v2-1-33bc58388ca5@oss.qualcomm.com