oc2g: generate failure event report in case of bad calibration
oc2g: generate failure event report in case of bad calibration

When the TX/RX calibration files can not be loaded a failure event
report should be sent to the BSC. Lets send a failure event report when
calbration data is either bad or can not be loaded (see also remvoed TODOs).

Change-Id: I3318470518b34807a443f7cb78c7091b4a3d4481
Related OS#3823

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