crypto: omap-sham - drop suspend and resume functions

Let's get rid of the suspend and resume calls to runtime PM as these calls
do not idle the hardware. The runtime suspend has been disabled for
system suspend since commit 88d26136

 ("PM: Prevent runtime suspend
during system resume").

Instead of runtime PM, the system suspend and resume functions should call
driver internal shared functions to idle the hardware as needed.

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>