msm: pm-8x60: Use generic clk apis during power collapse

The power management code calls in acpuclk code directly to switch to a
always on clock source during power collapse there by turning off the
HFPLL during any power collapse. The Krait clock management is switching
to use clocks ops model. To necessitate the change, the power management
code will register for CPU/L2 clock sources and disables the
corresponding clocks during power collapse.

Add a DT node to indicate if the clock sources are synchronized across
the cores/L2, to prevent querying on clock sources that might not be
available on certain targets. Also, clk_get() doesn't currently support
deferred probe, change the compile order to include pm-8x60 after clocks
driver to ensure that clock drivers get probed before pm-8x60.

Change-Id: I671296064dda93f1d2226e6ae059d827c4c00890
Signed-off-by: Mahesh Sivasubramanian <msivasub@codeaurora.org>
Signed-off-by: Vikram Mulukutla <markivx@codeaurora.org>