platform-msi: fix kernel-doc warnings

remove make W=1 warnings

drivers/base/platform-msi.c:336: warning:
Function parameter or member 'is_tree' not described in
'__platform_msi_create_device_domain'

drivers/base/platform-msi.c:336: warning:
expecting prototype for platform_msi_create_device_domain(). Prototype
was for __platform_msi_create_device_domain() instead
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20210331232614.304591-7-pierre-louis.bossart@linux.intel.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/base/platform-msi.c

@@ -316,10 +316,11 @@ void *platform_msi_get_host_data(struct irq_domain *domain)
 }
 
 /**
- * platform_msi_create_device_domain - Create a platform-msi domain
+ * __platform_msi_create_device_domain - Create a platform-msi domain
  *
  * @dev:		The device generating the MSIs
  * @nvec:		The number of MSIs that need to be allocated
+ * @is_tree:		flag to indicate tree hierarchy
  * @write_msi_msg:	Callback to write an interrupt message for @dev
  * @ops:		The hierarchy domain operations to use
  * @host_data:		Private data associated to this domain