grpahics/drm-fbsd12.0-kmod pkg-message should no longer describe installation of graphics/drm-legacy-kmod

[grahamperrin]

Hi

Under https://www.freshports.org/graphics/drm-fbsd12.0-kmod/#uses and in the packagesite.yaml for grpahics/drm-fbsd12.0-kmod:

… Older generations are supported by the legacy kms modules (radeonkms / i915kms) in base or by installing graphics/drm-legacy-kmod.

That part of the message is no longer appropriate.

From https://svnweb.freebsd.org/ports?view=revision&revision=559748:

Remove expired port:

2020-12-31 graphics/drm-legacy-kmod: Obsolete version, use drm-kmod