target-arm: Add ARMCPU field for Linux device-tree 'compatible' string

target-arm: Add ARMCPU field for Linux device-tree 'compatible' string

Linux requires device tree CPU nodes to include a 'compatible'
string describing the CPU. Add a field in the ARMCPU struct for
this so that boards which construct a device tree can insert
the correct CPU nodes.

Note that there is currently no officially specified 'compatible'
string for the TI925T, Cortex-M3 or SA1110 CPUs.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Message-id: 1385140638-10444-6-git-send-email-peter.maydell@linaro.org