ARM: debug: arrange Kconfig options more logically

Arrange the Kconfig options in rough alphabetical order, and place the
default 'none' and 'icedcc' options at the end.  This prefers the
platform specific debug option rather than the 'none' option, which is
what we actually want.

Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>