Kobo: Apply the AW99703 smooth ramp off fix to all affected devices

e.g., at least the Clara 2E features the same controller & driver,
but it is likely found on a few other models.

frontend/device/kobo/device.lua

@@ -432,11 +432,6 @@ local KoboCadmus = Kobo:extend{
         nl_min = 0,
         nl_max = 10,
         nl_inverted = false,
-        --- @note: The Sage natively ramps when setting the frontlight intensity.
-        ---        A side-effect of this behavior is that if you queue a series of intensity changes ending at 0,
-        ---        it won't ramp *at all*, and jump straight to zero.
-        ---        So we delay the final ramp off step to prevent (both) the native and our ramping from being optimized out
-        ramp_off_delay = 0.5,
     },
     boot_rota = C.FB_ROTATE_CW,
     battery_sysfs = "/sys/class/power_supply/battery",
@@ -639,6 +634,14 @@ function Kobo:init()
         end
     end
 
+    -- NOTE: Devices with an AW99703 frontlight PWM controller feature a hardware smooth ramp when setting the frontlight intensity.
+    ---      A side-effect of this behavior is that if you queue a series of intensity changes ending at 0,
+    ---      it won't ramp *at all*, jumping straight to zero instead.
+    ---      So we delay the final ramp off step to prevent (both) the native and our ramping from being optimized out.
+    if self:hasNaturalLight() and self.frontlight_settings.frontlight_mixer:find("aw99703", 12, true) then
+        self.frontlight_settings.ramp_off_delay = 0.5
+    end
+
     -- NOTE: i.MX5 devices have a wonky RTC that doesn't like alarms set further away that UINT16_MAX seconds from now...
     --       (c.f., WakeupMgr for more details).
     -- NOTE: getRTCName is currently hardcoded to rtc0 (which is also WakeupMgr's default).