ab8500_btemp: Ignore false btemp low interrupt

Ignore the low btemp interrupts for ab8500 3.0 and 3.3

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Hakan Berg <hakan.berg@stericsson.com>
Reviewed-by: Jonas ABERG <jonas.aberg@stericsson.com>
Tested-by: Marcus COOPER <marcus.xm.cooper@stericsson.com>
Signed-off-by: Anton Vorontsov <anton@enomsg.org>