driver-core: fix new kernel-doc warning in base/platform.c

Fix new kernel-doc warning in drivers/base/platform.c:

Warning(drivers/base/platform.c:528): No description found for parameter 'owner'

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>