arm64: dts: renesas: r9a09g077m44-rzt2h-evk: Clarify SD0 power jumpers

arm64: dts: renesas: r9a09g077m44-rzt2h-evk: Clarify SD0 power jumpers

Clarify the board setup requirements for using SDHI0 on the RZ/T2H EVK by
documenting the CN78 jumper positions needed to supply SD0 power for
either the default eMMC configuration or the SD card slot configuration.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://patch.msgid.link/20260123225957.1007089-3-prabhakar.mahadev-lad.rj@bp.renesas.com
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>