arm64: dts: renesas: r8a77990: Fix SCIF5 DMA channels

According to the R-Car Gen3 Hardware Manual Errata for Rev 1.50 of Feb
12, 2019, the DMA channels for SCIF5 are corrected from 16..47 to 0..15
on R-Car E3.

Signed-off-by: Takeshi Kihara <takeshi.kihara.df@renesas.com>
Fixes: a5ebe5e4

 ("arm64: dts: renesas: r8a77990: Add SCIF-{0,1,3,4,5} device nodes")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>