emulators/rtc: update 2004.02.24.1 -> 2020.07.07.1

• submitter becomes maintainer
• Install kmod into /boot/modules instead of /usr/local
• Cleared out bits dating back to pre-devfs
• Removed #ifdef bits related to FreeBSD <= 4.X and FreeBSD <= 8.X
• Olegs fixes for FreeBSD 11.X and FreeBSD 12.X+
• Removed "USES= linux uidfix" - whilst this provides functionality that is "often" used by linux programs, that's not necessarily the case, and this module doesn't require any linux subsystem or kernel MOD to operate.
• Removed oldstyle rtc.sh - include pkg-message showing how to load from the rc.conf "kld_list" mechanism.
• Fixed typo in "test.c" -> /dec -> /dev
• Fixed path to "rtc.h" in "test.c"

PR: 233057
Submitted by: Jamie Landeg-Jones <jamie@catflap.org>