Rename filter1,2 to filter_m0,1

Automatically clear certain bits when reading INT_FLAG

merge: let 3x oversampling clock error does not accumulate beyond one…

… byte

let 3x oversampling clock error does not accumulate beyond one byte

make sure to calculate the timeout with DIV_LS

make sure to calculate the timeout with DIV_LS

increase multicast filter to 2

rx: fixed an issue where idle_wait_len was one bit shorter