x86, doc: Document that bootloader ID 4 is used also by iPXE

Etherboot -> gPXE -> iPXE...

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: Michael Brown <mbrown@fensystems.co.uk>
This commit is contained in:
H. Peter Anvin 2012-12-12 20:28:39 -08:00
commit cd34ab8b16