remoteproc: mediatek: Support setting DRAM and IPI shared buffer sizes

The SCP on different chips will require different DRAM sizes and IPI
shared buffer sizes based on varying requirements.

Signed-off-by: Olivia Wen <olivia.wen@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20240430011534.9587-4-olivia.wen@mediatek.com
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>