arm64: dts: rockchip: Fix bluetooth properties on Rock960 boards

[ Upstream commit ea74528aaea5a1dfc8e3de09ef2af37530eca526 ]

The expected clock-name is different, and extclk also is deprecated
in favor of txco for clocks that are not crystals.

So fix it to match the binding.

Fixes: c72235c2 ("arm64: dts: rockchip: Add on-board WiFi/BT support for Rock960 boards")
Cc: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Dragan Simic <dsimic@manjaro.org>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Link: https://lore.kernel.org/r/20241008203940.2573684-5-heiko@sntech.de


Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>