gsm_08_58.h: introduce RSL_CHAN_NR_1 constant

Using the RSL_CHAN_* constants, we sometimes need to add 1 to the chan bits
to indicate e.g. the second TCH/H channel.

RSL_CHAN_NR_1 marks this lowest channel bit that needs to be added.

The name is analogous to RSL_CHAN_NR_MASK.

Change-Id: Iea06432039d1cd23cc6b5acec308bb829b596d47
1 file changed