bone.js Pinmux Value Missing? P9_25

I'm still learning BBB, device trees, how to parse the bone.js pins, etc. etc. But looking at lines [4975-4983](https://github.com/jadonk/bonescript/blob/master/src/bone.js#L4975-L4983) the options seem to be missing mode 5 & 6 which is listed in a few different references one being [this one](https://ofitselfso.com/BeagleNotes/BeagleboneBlackPRUInputPinMuxModes.pdf). I know there's a mode 6, I can set it and use it.

`pr1_pru0_pru_r31_7`
`pr1_pru0_pru_r30_7`

Start by reading src/bone.js lines 4975-4983 and compare the P9_25 pin definitions with the referenced BeagleBone pinmux modes. Confirm how modes 5 and 6 are represented, including pr1_pru0_pru_r31_7 and pr1_pru0_pru_r30_7. The issue is done when P9_25 exposes the missing modes without disrupting its existing pin parsing.

Written by the indexing model from the issue text.