dt-bindings: power: Add R8A779G0 V4H SYSC power domain definitions

Add power domain indices for R-Car V4H (R8A779G0) from Linux next
commit 058f4df42121 ("Add linux-next specific files for 20230228")

Reviewed-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
Signed-off-by: Tho Vu <tho.vu.wh@renesas.com>
Signed-off-by: Hai Pham <hai.pham.ud@renesas.com>
Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
[Marek: Update to linux next 20230228 state]