hwmon: (da9055) Remove use of regmap_irq_get_virq()

Remove use of regmap_irq_get_virq() in driver probe which was
conflicting with use of platform_get_irq_byname().
platform_get_irq_byname() already returns the VIRQ number due
to MFD core translation so using regmap_irq_get_virq() on that
returned value results in an incorrect IRQ being requested.
The driver probes then fail because of this.

Signed-off-by: Adam Thomson <Adam.Thomson.Opensource@diasemi.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>