ASoC: Intel: Skylake: Simplify m_state for loadable modules

States SKL_MODULE_LOADED and SKL_MODULE_UNLOADED are redundant with
'loadable' flag in struct skl_module. Additionally
skl_tplg_mixer_dapm_post_pmd_event() sets m_state always to
SKL_MODULE_UNINIT so next unload function isn't called for such modules.

Signed-off-by: Gustaw Lewandowski <gustaw.lewandowski@linux.intel.com>
Signed-off-by: Cezary Rojewski <cezary.rojewski@intel.com>
Tested-by: Lukasz Majczak <lma@semihalf.com>
Link: https://lore.kernel.org/r/20210818075742.1515155-8-cezary.rojewski@intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>