BeagleBone-black GPIO pins use on FreeBSD

[Luiz Otavio O Souza]

Hi,

I've updated the BeagleBone-black Wiki page
(https://wiki.freebsd.org/FreeBSD/arm/BeagleBoneBlack) with the
default settings for the GPIO expansion headers on FreeBSD.

It has all the pins used for ADC (AIN), I2C, PWMs and MMC1.

Please let me know if i have missed something.

I hope this saves some time for people who is going to work with GPIO.

Regards,
Luiz