arm64: dts: renesas: r8a774c0: Fix MSIOF1 DMA channels

According to Technical Update TN-RCT-S0352A/E, MSIOF1 DMA can only be
used with SYS-DMAC0 on R-Car E3.

Fixes: 62c0056f ("arm64: dts: renesas: r8a774c0: Add MSIOF nodes")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20200917132117.8515-3-geert+renesas@glider.be