USB: phy: msm: Fix out of bound access

When invalid value passed from user-space to modify the
POWER_SUPPLY_HEALTH property for eg)
echo 500 > /sys/devices/soc/78db000.usb/power_supply/usb/health
out of bound access happens while power_supply uevent updating
all power_supply properties due to change of power_supply
property. Fix this by adding proper check before modifying
POWER_SUPPLY_HEALTH property.

CRs-Fixed: 2068932
Change-Id: Ib6679d7045429146a56075caccd3dd8c0cb12dff
Signed-off-by: Arumuga Durai A <cadurai@codeaurora.org>