hw/pl061.c: Implement ARM PL061 as well as Luminary one ARM's PL061 has a different set of ID registers to the one in the Luminary Stellaris; implement this so that the Linux driver can identify the Realview PBX PL061 correctly. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>