lp8727_charger: Use IRQF_ONESHOT

Generated by: scripts/coccinelle/misc/irqf_oneshot.cocci

ERROR: Threaded IRQ with no primary handler requested without IRQF_ONESHOT

Make sure threaded IRQs without a primary handler are always request
with IRQF_ONESHOT

Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Acked-by: Milo(Woogyom) Kim <milo.kim@ti.com>
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>