target/arm: Rename CP_ACCESS_TRAP_UNCATEGORIZED to CP_ACCESS_UNDEFINED

target/arm: Rename CP_ACCESS_TRAP_UNCATEGORIZED to CP_ACCESS_UNDEFINED

CP_ACCESS_TRAP_UNCATEGORIZED is technically an accurate description
of what this return value from a cpreg accessfn does, but it's liable
to confusion because it doesn't match how the Arm ARM pseudocode
indicates this case. What it does is an EXCP_UDEF with a zero
("uncategorized") syndrome value, which is what an UNDEFINED instruction
does. The pseudocode uses "UNDEFINED" to show this; rename our
constant to CP_ACCESS_UNDEFINED to make the parallel clearer.

Commit created with
sed -i -e 's/CP_ACCESS_TRAP_UNCATEGORIZED/CP_ACCESS_UNDEFINED/' $(git grep -l CP_ACCESS_TRAP_UNCATEGORIZED)

plus manual editing of the comment.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20250130182309.717346-14-peter.maydell@linaro.org