The description of the options starts at column 16, so fix
this in some runaway lines for a more uniform output.

While we're at it, replace the capital "NOTE" with "Note"
since this seems to be the more common capitalization in
qemu-options.hx.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>