ARM: dts: r8a7745: Add MSIOF[012] support

Add the DT nodes needed by MSIOF[012] interfaces to the SoC dtsi.
Also, define aliases for spi[123].

Signed-off-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
Signed-off-by: Chris Paterson <chris.paterson2@renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>