ACPI: docs: enumeration: Amend PWM enumeration ASL example

Drop blank line and add a closing curly brace to make ASL example closer
to the reality.

Fixes: ef3d13b867 ("docs: firmware-guide: ACPI: Add a PWM example")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Documentation/firmware-guide/acpi/enumeration.rst

@@ -277,9 +277,9 @@ introduced, i.e.::
                     }
                 }
             }
-
         })
         ...
+    }
 
 In the above example the PWM-based LED driver references to the PWM channel 0
 of \_SB.PCI0.PWM device with initial period setting equal to 600 ms (note that