Refactor DSP init routines so there is a dedicated init function
for the stages that need it. Remove the DSP_INIT configure message.
This allows the init code to be safely marked INIT_ATTR, saving a
bit of code size, and allowing the linker to verify that there are
no unsafe references to the init routines.
Change-Id: I1702f0f579bbb300a6fe7d0e67b13aa2e9dd7f8a
Makes dsp_sample_input.c a bit less messy, and dependencies
are more explicit. There's possibly a minor loss of inlining
but it isn't a big deal.
Change-Id: I30f923a0ca758f2b113d32852d1f65586dff0cd1