osmo-bts-virtual.cfg: ms-power-control dsp -> osmo
osmo-bts-virtual.cfg: ms-power-control dsp -> osmo

Fix error while starting osmo-bts-virtual with the example config:
"This BTS model has no DSP/HW MS Power Control support"

Fixes: c693067b7e99a643da673cb3e2a36162cbd0f59c ("Introduce BTS feature BTS_FEAT_MS_PWR_CTRL_DSP")
Change-Id: I4f9a06e85d58294719a24197eb1c42a69fbd03d6

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