This is a preparation for ICL TC cold exit sequences.

v2:
- renamed new functions to hsw_power_well_enable_prepare()/complete()
Signed-off-by: NJosé Roberto de Souza <jose.souza@intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Tested-by: NYou-Sheng Yang <vicamo.yang@canonical.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200414194956.164323-3-jose.souza@intel.com