firmware_loader: fix a kernel-doc markup

The firmware_fallback_sysfs had some changes at their
parameters. Those ended by dropping a documentation for
such parameter. Re-add it.

Fixes: 89287c16 ("firmware: Store opt_flags in fw_priv")
Fixes: c2c07616 ("firmware_loader: change enum fw_opt to u32")
Signed-off-by: NMauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/23ec441bb9c206f5899b5d64d34e5c9f6add5fd9.1601990386.git.mchehab+huawei@kernel.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/base/firmware_loader/fallback.c

@@ -623,6 +623,8 @@ static bool fw_run_sysfs_fallback(u32 opt_flags)
  * @fw: pointer to firmware image
  * @name: name of firmware file to look for
  * @device: device for which firmware is being loaded
+ * @opt_flags: options to control firmware loading behaviour, as defined by
+ *	       &enum fw_opt
  * @ret: return value from direct lookup which triggered the fallback mechanism
  *
  * This function is called if direct lookup for the firmware failed, it enables