LPC178x/LPC40xx: lpc24xx_pin_set_function() keep LPC4088 W type pin in digital mode for non-analog function.
The problem wit incorrect switching of pins into analog mode manifests
on LPC4088 based board.
LPC4088 implements pin P1.17 (ENET_MDIO) as new W type (digital pin
with analog option). The pin was listed as D category on LPC1788
which does not have analog mode control bit. If analog option is
not explicitly switched off on LPC4088 then the pin does not work
as digital pin.