sysutils/devcpu-data: Split off two new ports for vendor data

sysutils/devcpu-data is now just an RC script that optionally depends on
two new ports, sysutils/devcpu-data-amd and sysutils/devcpu-data-intel.
The two new ports each contain vendor microcode data.

While here:

• Set missing license information. The license was obtained from

https://git.kernel.org/pub/scm/linux/kernel/git/firmware/linux-firmware.git/tree/LICENSE.amd-ucode

• Update varaible ordering per portclippy

Reviewed by: decke, emaste, markj
Approved by: sbruno (maintainer)
Differential Revision: https://reviews.freebsd.org/D32349