[PATCH] arm26:cleanup trap handling assembly

This removes some unneeded definitions and makes the naming used within the
file more consistent.

Also adds some macros to make it easier to see how the interrupt handler is
structured.

The assembled output is identical to the original.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>