drm: Install pwm modules on all architectures

At least on x86 on Bay and Cherry Trail devices the pmw-lpss modules must
be in the initrd too, otherwise the i915 driver will still load, but
it will report the following error:

[drm:pwm_setup_backlight [i915]] *ERROR* Failed to own the pwm chip

And not register /sys/class/backlight/intel_backlight and users will
not be able to control their backlight.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>

modules.d/50drm/module-setup.sh

@@ -21,12 +21,11 @@ installkernel() {
             "=drivers/gpu/drm/i2c" \
             "=drivers/gpu/drm/panel" \
             "=drivers/gpu/drm/bridge" \
-            "=drivers/pwm" \
             "=drivers/video/backlight" \
             ${NULL}
     fi
 
-    instmods amdkfd hyperv_fb
+    instmods amdkfd hyperv_fb "=drivers/pwm"
 
     # if the hardware is present, include module even if it is not currently loaded,
     # as we could e.g. be in the installer; nokmsboot boot parameter will disable