m68k: atari: Document data parameter of stdma_try_lock()

When building with W=1:

arch/m68k/atari/stdma.c:69: warning: Function parameter or member 'data' not described in 'stdma_try_lock'

Fix this by documenting the data parameter.

Signed-off-by: Geert Uytterhoeven <[e-mail]>
Acked-by: Arnd Bergmann <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

arch/m68k/atari/stdma.c

···
 /**
  * stdma_try_lock - attempt to acquire ST DMA interrupt "lock"
  * @handler: interrupt handler to use after acquisition
+ * @data: cookie passed to the interrupt handler function
  *
  * Returns !0 if lock was acquired; otherwise 0.
  */