qcom: qpnp-haptic: Disable haptics when enable time specified is zero

The vibrator HAL expects vibration to be disabled when the 'enable'
time specified is 0. Fix this.

CRs-Fixed: 2083994
Change-Id: I12843233da5429ed2fd53f33617952b1dd0ddcd5
Signed-off-by: Anirudh Ghayal <aghayal@codeaurora.org>