ARM: dts: r8a7778: Add HSCIF0/1 support

Add HSCIF0/1 clocks and device nodes, based on Rev. 1.00 of the R-Car
M1A datasheet.

Signed-off-by: Ulrich Hecht <ulrich.hecht+renesas@gmail.com>
[geert: Squashed two patches]
[geert: Correct HSCIF1 module clock index]
[geert: Correct reg properties for non-LPAE]
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>