arm64: dts: rockchip: Rename vdec_mmu node for RK3328

All other rockchip devices which have vdec nodes do not
have an rk prefix. Remove the prefix from the (currently
unused) rkvdec_mmu node for consistency with other
devices.

Signed-off-by: Christopher Obbard <chris.obbard@collabora.com>
Reviewed-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Link: https://lore.kernel.org/r/20220425184510.1138446-3-chris.obbard@collabora.com


Signed-off-by: Heiko Stuebner <heiko@sntech.de>