riscv: defconfig: Disable RZ/Five peripheral support

There is not much point in keeping support for RZ/Five peripherals
enabled, as the RZ/Five platform option (ARCH_R9A07G043) is gated behind
NONPORTABLE.  Hence drop all config options that enable built-in or
modular support for peripherals found on RZ/Five SoCs.

Disable USB_XHCI_RCAR explicitly, as its value defaults to the value of
ARCH_RENESAS, which is still enabled.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Link: https://lore.kernel.org/r/89ad70c7d6e8078208fecfd41dc03f6028531729.1722353710.git.geert+renesas@glider.be


Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>