PWM with Vanilla Kernel on Lime2?

I'm using an Olimex LIME2 board with an A20 processor (actually it's a Olimex A20-SOM, but that shouldn't matter) and trying to use PWM.

I have an older image (jessie with Kernel 3.4) where the PWM hardware can be accessed through /sys/class/pwm-sunxi/pwm*/{duty, duty_percent, period, pin, polarity, pulse, run}.

Now I'm building a newer image (xenial with Vanilla kernel). It has /sys/class/pwm, but the directory is empty. Any ideas?

The fex file is the same for both boards; the relevant section is:

[pwm0_para]
pwm_used = 1
pwm_period = 10000
pwm_duty_percent = 50

[pwm1_para]
pwm_used = 1
pwm_period = 10000
pwm_duty_percent = 50