Documentation: devres: add missing devm_acpi_dma_controller_free() helper

Add missing devm_acpi_dma_controller_free() to devres.rst, it's introduced
by commit 1b2e98bc ("dma: acpi-dma: introduce ACPI DMA helpers").

Fixes: 1b2e98bc ("dma: acpi-dma: introduce ACPI DMA helpers")
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Vinod Koul <vinod.koul@intel.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20221102022701.1407289-1-yangyingliang@huawei.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

Documentation/driver-api/driver-model/devres.rst

@@ -437,6 +437,7 @@ SERDEV
 
 SLAVE DMA ENGINE
   devm_acpi_dma_controller_register()
+  devm_acpi_dma_controller_free()
 
 SPI
   devm_spi_alloc_master()