power: smb358-charger: fix disabling APSD

Currently if APSD is disabled then junk is written to the APSD
enable register. Fix it by writing 0 to the register instead.

CRs-Fixed: 889437
Change-Id: I9b86b521630a03b38b16ecc2e82c7e525e65643a
Signed-off-by: Nicholas Troast <ntroast@codeaurora.org>
Signed-off-by: Ashay Jaiswal <ashayj@codeaurora.org>