msm: clock-8960/8660/9615: Fix pcm clock initial rate

If the pcm clock is not handed off via clock handoff the rate of
pcm is set to 0. In this case, clk_set_rate() of zero would not
program the hardware to select the external input. Therefore set
the rate of the clock to some large initial value so that
clk_set_rate(0) will work properly.

Change-Id: I2555cf2bd1984e8ede5a2b537a3a7dd60034fcf5
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>