target/arm: Make rvbar settable after realize

Make the rvbar property settable after realize. This is done
in preparation to model the ZynqMP's runtime configurable rvbar.

Signed-off-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Message-id: 20220316164645.2303510-3-edgar.iglesias@gmail.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
3 files changed