Update sysutils/cpupdate:

• sync with platomav/CPUMicrocodes MCE DB r64;
• remove useless use of subshell;
• rcorder runs /etc/rc.d/sysctl before FILESYSTEMS to process /etc/sysctl.conf so let cpupdate's startup script automatically enable Indirect Branch Restricted Speculation after successful start of ${PRERIX}/sbin/cpupdate, if possible, unless this is disabled with new "cpupdate_irbs_enable" rc.conf variable;
• bump PORTREVISION.