doc: add novamap to efi kernel command line parameters

Document the efi=novamap kernel command line parameter.
Put the efi parameters into alphabetic order.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Link: https://lore.kernel.org/r/20200616104012.4780-1-xypron.glpk@gmx.de


Signed-off-by: Jonathan Corbet <corbet@lwn.net>