MAINTAINERS: add qcom clocks to the maintainers list

This patch adds qcom clock drivers to the QCOM/MSM support list so that
get_maintainer.pl can pick up correct cc list.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Andy Gross <andy.gross@linaro.org>