MAINTAINERS: Qualcomm: add some missing paths

Add drivers and DTS files, as well as regex matches for
qcom/qualcomm/snapdragon.

Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Reviewed-by: Sumit Garg <sumit.garg@linaro.org>
Signed-off-by: Caleb Connolly <caleb.connolly@linaro.org>