The q6asm_dai_hardware_capture structure is only copied into another
structure, so make it const.

The opportunity for this change was found using Coccinelle.
Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Link: https://lore.kernel.org/r/1577864614-5543-11-git-send-email-Julia.Lawall@inria.frSigned-off-by: Mark Brown <broonie@kernel.org>