mfd: Remove ezx-pcap defines for custom led gpio encoding

We used these, in a first version of leds-pcap driver, in order to encode gpio
enabling and gpio inversion for a led inside the variable used for the gpio
number. In the new leds-pcap driver we rely on gpio_is_valid() to derive if a
led is gpio enabled and we have a dedicated flag to tell if the gpio value has
to be inverted.

Signed-off-by: Antonio Ospite <ospite@studenti.unina.it>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>