phy: mapphone-mdm6600: Add missing description for some structure fields

We get warning with W=1 build:
drivers/phy/motorola/phy-mapphone-mdm6600.c:185: warning: Function
parameter or member 'val' not described in 'phy_mdm6600_cmd'
drivers/phy/motorola/phy-mapphone-mdm6600.c:200: warning: Function
parameter or member 'work' not described in 'phy_mdm6600_status'

Fix that by adding description for 'val' and 'work'

Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Vinod Koul <[e-mail]>

drivers/phy/motorola/phy-mapphone-mdm6600.c

···
 /**
  * phy_mdm6600_cmd() - send a command request to mdm6600
  * @ddata: device driver data
+ * @val: value of cmd to be set
  *
  * Configures the three command request GPIOs to the specified value.
  */
···
 
 /**
  * phy_mdm6600_status() - read mdm6600 status lines
- * @ddata: device driver data
+ * @work: work structure
  */
 static void phy_mdm6600_status(struct work_struct *work)
 {