Document reserved SRAM for the SMP jump stub on Renesas R-Car Gen2 and RZ/G1 SoCs. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Simon Horman <horms+renesas@verge.net.au>