mfd: ab8500-core: Show turn on status at boot

Several states can be detected when a device is initially turned on.
This patch displays these states in the log. If none of the states
are true, then we report that too.

Signed-off-by: Mattias Wallin <mattias.wallin@stericsson.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Reviewed-by: Marcus COOPER <marcus.xm.cooper@stericsson.com>
Reviewed-by: Jonas ABERG <jonas.aberg@stericsson.com>
Acked-by: Samuel Ortiz <sameo@linux.intel.com>