I think the Main DT doesn't specify the pin PA5, but the /boot/dtb/overlay/sun8i-h3-pwm.dtbo overlay does ...
So, better use that overlay, simply by adding "overlays=pwm" in the /boot/armbianEnv.txt and reboot.
I did some tests on my OPiZero and it worked, adjusting the period and duty-cycle, etc ...
Ok ! You probably have this error in "dmesg" like I got :
sun4i-usb-phy 1c19400.phy: Couldn't request ID GPIO
This is a bug probably introduced several months ago !
I don't have yet a real solution/fix, but at least I have a workaround :
Download the DT compiler using "wget http://ftp.debian.org/debian/pool/main/d/device-tree-compiler/device-tree-compiler_1.4.7-3_armhf.deb " , and then installing it using "dpkg -i device-tree-compiler_1.4.7-3_armhf.deb"
Then, decompile current DTB into DTS using "dtc -@ -I dtb -O dts -o sun8i-h3-orangepi-one.dts /boot/dtb/sun8i-h3-orangepi-one.dtb".
Edit this DTS to change "dr_mode" from "otg" to "host" in the "usb@1c19000" node, and comment out the "usb0_id_det-gpios" line in the "phy@1c19400" node.
Recompile DTB from this DTS "dtc -@ -I dts -O dtb -o /boot/dtb/sun8i-h3-orangepi-one.dtb sun8i-h3-orangepi-one.dts" and then reboot. The USB0 should be powered ...