ab8500_btemp: Detect battery type in workqueue

Detect battery type in work queue instead of probe.

This reduces the system boot time with 1.5s.

Signed-off-by: Jonas Aaberg <jonas.aberg@stericsson.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Reviewed-by: Karl KOMIEROWSKI <karl.komierowski@stericsson.com>