[PATCH][POWERPC] document ipic level/sense info

[Segher Boessenkool]

> +Sense and level information follows the Linux convention
> +(specified in include/linux/interrupt.h) and should be encoded
> +as follows:
> +
> +	1 =  low to high edge sensitive type enabled
> +	2 =  high to low edge sensitive type enabled
> +	4 =  active high level sensitive type enabled
> +	8 =  active low level sensitive type enabled

Please note that using the same bit encoding as some Linux
version does buys you (almost) nothing; a good parser for
this OF node should do range/value checking on this property
anyway, translating the values in the process costs nothing.


Segher