ARM: dts: sun8i: h2-plus: bananapi-m2-zero: Increase BT UART speed

Bluetooth module on BananaPi M2 Zero can also be used for streaming
audio. However, for that case higher UART speed is required.

Add a max-speed property.

Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net>
Acked-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20210116103710.245617-1-jernej.skrabec@siol.net

arch/arm/boot/dts/sun8i-h2-plus-bananapi-m2-zero.dts

@@ -154,6 +154,7 @@
 
 	bluetooth {
 		compatible = "brcm,bcm43438-bt";
+		max-speed = <1500000>;
 		clocks = <&rtc 1>;
 		clock-names = "lpo";
 		vbat-supply = <&reg_vcc3v3>;