ARM: dts: r8a7779: Add HSCIF0/1 device nodes

Based on Rev. 1.00 of the R-Car H1 datasheet.

Signed-off-by: Ulrich Hecht <uli+renesas@fpond.eu>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>