ASoC: SOF: Intel: hda-dsp: Declare locally used functions as static

ASoC: SOF: Intel: hda-dsp: Declare locally used functions as static

The following functions can be made static as they are only used locally:
hda_dsp_core_reset_enter
hda_dsp_core_reset_leave
hda_dsp_core_stall_reset
hda_dsp_core_power_up
hda_dsp_core_power_down
hda_dsp_core_is_enabled

The hda_dsp_ipc_int_disable is also only used within hda-dsp.c, but for
symmetry for hda_dsp_ipc_int_enable (used by hda-loader.c) leave it as it
is.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@linux.intel.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
Reviewed-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Link: https://lore.kernel.org/r/20210915071805.5704-2-peter.ujfalusi@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>