ARM: dts: R-Car Gen1 board comment update

Include R-Car Gen1 product names for Bock-W and Marzen.

The product names are taken from:
Documentation/devicetree/bindings/arm/shmobile.txt

Signed-off-by: Magnus Damm <damm@opensource.se>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>