The IPA_POWER_FLAG_RESUMED was originally used to avoid calling
pm_wakeup_dev_event() more than once when handling a SUSPEND
interrupt.  This call is no longer made, so there' no need for the
flag, so get rid of it.

That leaves no more IPA power flags usefully defined, so just get
rid of the bitmap in the IPA power structure and the definition of
the ipa_power_flag enumerated type.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>