Enable r8a7740 Multiplatform support for the generic r8a7740
machine vector. No board support is enabled, and the board
code for Armadillo 800 EVA DT Reference is left by itself.
Signed-off-by: Magnus Damm <damm+renesas@opensource.se> Signed-off-by: Simon Horman <horms+renesas@verge.net.au>