cs: Add GprsCodingScheme::optionalPaddingBits

Return the amount of optional padding bits, which is 6*8 for
MCS-3 and MCS-6 and 0 for all other coding schemes. The padding
is needed the encode 68 byte data blocks (MCS-8) with these schemes.
See TS 44.060, 9.3.2.1 and Annex J for details.

Sponsored-by: On-Waves ehf
3 files changed