x86, doc: Assign a bootloader ID for "Minimal Linux Bootloader"

Assign a bootloader ID for Sebastian Plotz' "Minimal Linux Bootloader"
(http://sebastian-plotz.blogspot.de

).  Sebastian has agreed to make
this the pilot for the use of extended boot loader IDs, so this is
assigned version ID 0x11 (avoid assigning 0x10 for now to catch bugs
with people putting E in the primary ID but leaving the extended ID as
zero.)

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: Sebastian Plotz <sebastian-plotz@web.de>
Link: http://lkml.kernel.org/n/tip-nq318h0okuaem8x9dpv9854k@git.kernel.org