power: smb1390: add support to configure temp alarm threshold

Add support to configure temp alarm threshold for SMB1390
die-temp via device tree. If DT property is not specified the
default temperature threshold is set to 110 DegC.

Change-Id: Icd9e94c241deea33687769043810c848c0a682ed
Signed-off-by: Ashay Jaiswal <ashayj@codeaurora.org>
Signed-off-by: Guru Das Srinagesh <gurus@codeaurora.org>