rM: Unbreak PowerEvents (#7043)

Most of this is scheduled with delays for reasons, so this was a stupid
idea, my bad ;).

Fix #7033

frontend/device/remarkable/device.lua

@@ -141,13 +141,7 @@ function Remarkable:setDateTime(year, month, day, hour, min, sec)
     return os.execute(command) == 0
 end
 
-function Remarkable:_clearScreen()
-    self.screen:clear()
-    self.screen:refreshFull()
-end
-
 function Remarkable:suspend()
-    self:_clearScreen()
     os.execute("systemctl suspend")
 end
 
@@ -155,12 +149,10 @@ function Remarkable:resume()
 end
 
 function Remarkable:powerOff()
-    self:_clearScreen()
     os.execute("systemctl poweroff")
 end
 
 function Remarkable:reboot()
-    self:_clearScreen()
     os.execute("systemctl reboot")
 end