arm64: dts: renesas: r9a07g043: Split out RZ/G2UL SoC specific parts

arm64: dts: renesas: r9a07g043: Split out RZ/G2UL SoC specific parts

Move RZ/G2UL SoC specific parts to r9a07g043u.dtsi so that
r9a07g043.dtsi can be shared with RZ/Five (RISC-V SoC).

Below are the changes due to which SoC specific parts are moved to
r9a07g043u.dtsi:
  - RZ/G2UL has Cortex-A55 (ARM64) whereas RZ/Five has AX45MP (RISC-V),
  - RZ/G2UL has GICv3 as interrupt controller whereas RZ/Five has PLIC,
  - RZ/G2UL has interrupts for SYSC block whereas interrupts are missing
    for SYSC block on RZ/Five,
  - RZ/G2UL has armv8-timer whereas RZ/Five has riscv-timer,
  - RZ/G2UL has PSCI whereas RZ/Five have OpenSBI.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Link: https://lore.kernel.org/r/20221025220629.79321-3-prabhakar.mahadev-lad.rj@bp.renesas.com
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>