*/*: Sunset 12.4-RELEASE/12-STABLE from ports tree

- Remove all references to defunct ARCH arm
- Remove all references to defunct ARCH sparc64
- Remove x11-drivers/xf86-video-sunffb which requires defunct sparc64
  ARCH
- Remove sysutils/afbinit requires defunct sparc64 ARCH
- Remove all references to bktr driver
- Remove all references to defunct FreeBSD_12
- Remove all references to OSVERSION/OSREL corresponding to 12
- Remove conditionals in Mk/Uses/cabal.mk
- Remove sparc reference from Mk/Uses/qt-dist.mk
- Remove BROKEN_sparc64/NOT_FOR_ARCH=sparc64
- Remove BROKEN_FreeBSD_12* from:
- Remove OpenSSL patches from:
- Remove conditional flags for OSVERSION >= 1300000 to fixed flags.
  Also move conditional flags for non sparc64/arm ARCH to fixed flags.

Reviewed by:	brooks, jbeich, rene, salvadore
Differential Revision: https://reviews.freebsd.org/D42068