multimedia/mpv: 0.91 -> 0.92

• Update audio/ladspa LIB_DEPENDS to new format
• Update to 0.92

Changes:

https://github.com/mpv-player/mpv/releases/tag/v0.9.2

PR: 200380
Submitted by: Carlos Jacobo Puga Medina <cpm@fbsd.es> (maintainer)