target/arm: A32, T32: Create Instruction Syndromes for Data Aborts

Add support for generating the ISS (Instruction Specific Syndrome)
for Data Abort exceptions taken from AArch32. These syndromes are
used by hypervisors for example to trap and emulate memory accesses.

This is the equivalent for AArch32 guests of the work done for AArch64
guests in commit aaa1f954.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>