mfd: tps65218: Make INT1 our status_base register

If we don't tell regmap-irq that our first status
register is at offset 1, it will try to read offset
zero, which is the chipid register.

Fixes: 44b4dc61 mfd: tps65218: Add driver for the TPS65218 PMIC
Cc: <stable@vger.kernel.org> # v3.15+
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>