clk: qcom: msm8916: Move xo and sleep clocks into DT

Move the xo and sleep clocks to device-tree, instead of hard-coding
them in the driver. This allows us to insert the RPM clocks (if they
are enabled) in between the on-board oscillators and the actual clock.

Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>