The AT91x40 family doesn't have the debug unit like its bigger brothers.
But it does have the ID and extension registers (with the bit meanings
the same). Reorganize at91_dbgu.h to cater for this.

This also affects the load uncompressor, since it outputs to the
debug port.
Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Acked-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>