11bit RACH support for osmo-bts-litecell15
11bit RACH support for osmo-bts-litecell15

Based on the indication from L1, number of bits in RACH and burst
type is determined. Appropriate parameters are filled in
osmo-bts-litecell15. These parameters are sent to osmo-pcu for
processing of the RACH.

Change-Id: Ie5207a15424fb287febf74e830297531232accde

osmocom/osmo-bts,osmocom/osmo-bts,osmocom/osmo-bts