Enable sh73a0 Multiplatform support for the generic sh73a0
machine vector. No board support is enabled, and the board
code for KZM9G DT Reference is left by itself.
Signed-off-by: NMagnus Damm <damm+renesas@opensource.se>
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NSimon Horman <horms+renesas@verge.net.au>