[ARM] SMDK6410: Use active high IRQ for the WM8350 on the WM1190-EV1

Using an active high IRQ ensures that the WM8350 interrupt handling
does not spin when used with a SMDK6410 which has not had R20 removed
and R21 fitted to connect EINT12 to the PMIC module rather thant the
fixed regulators on the CPU module.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>