refactor(platforms): remove usage of psci_power_down_wfi

The callers in PSCI will now call wfi() after calling the
pwr_domain_pwr_down() platform hook (previously they were mutually
exclusive). As such, there is no need for platforms to do this
themselves. In fact, it is strongly advisable for platforms not to do
this themselves so that the PSCI can apply any relevant errata
mitigations.

Change-Id: Ic9702edef7503996be24d984e29dfcc13bc3fcba
Signed-off-by: Boyan Karatotev <boyan.karatotev@arm.com>
11 files changed