ARM: shmobile: armadillo800eva reference: Remove DTS

The r8a7740 Armadillo800EVA DTS can now be used both for
DT Multiplatform and the legacy case. Because of that
remove the r8a7740 Armadillo800EVA DT reference DTS file.

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