power: supply: smb5: Only enable temp change IRQ when VBUS present

When ADC based die temperature ICL regulation is enabled, there may be a
storm of temp-change IRQs due to the charger temperature block being
enabled and disabled. This primarily occurs when a legacy type-C cable
is left floating from the charger side. Prevent this by enabling
temp_change IRQ only when VBUS is present.

CRs-Fixed: 2413977
Change-Id: Iea1dc6d5f0c11026a33753c021bab593a21983ef
Signed-off-by: Fenglin Wu <fenglinw@codeaurora.org>