crypto: omap-sham - add missing pm_runtime_dontuse_autosuspend()

We should pair the usage of pm_runtime_use_autosuspend() with
pm_runtime_dont_use_autosuspend().

Cc: Lokesh Vutla <lokeshvutla@ti.com>
Cc: Tero Kristo <kristo@kernel.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>