kernel: Generate miidevs.h, pccarddevs.h and pcidevs.h on the fly.

It removes the need to regenerate those header file after first editing
the associated list of IDs (miidevs, pccarddevs or pcidevs). After this
commit, editing the list alone is enough to add IDs.

We already did it like that for usb4bsd's usbdevs.h before. This commit
adjusts things for the remaining ID lists.
Remove old {pccard,pci,usb}devs.h via 'make upgrade'.
kernel: Clean up sys/kern/Makefile and sys/emulation/linux/i386/Makefile

* Move generation of syscall related files from Makefile.misc to
  Makefile.

* Remove Makefile.misc, since the rest of its content (in sys/kern at
  at least) is inactive code for tags and links generation.