ASoC: Fix for SSR issue on msm8953

Initial_boot flag is applicable only if audio_pdr service
is registered. For targets like msm8953 pdr is
disabled and SSR service is used. Use this flag
accordingly so that the codec power_down and power_up
events are processed even when SSR service is active.

Change-Id: Idab9e6abc6e0b4296f0356c6810885477b9fd6cd
Signed-off-by: Shashi Kant Maurya <smaury@codeaurora.org>