inclusion of right after sys/param.h.
o Only vt_core module use compat options, move it from common header to module.
Reported by: Larry Rosenman ler at lerctr dot org
Sponsored by: The FreeBSD Foundation
o Include opt_splash.h for vt(9) to know when splash device is enabled.
o Build logo_freebsd.c only if splash and vt are enabled.
o Include opt_compat.h to know when we have to respect compatibility.
Sponsored by: The FreeBSD Foundation