crypto: ccree - remove unneeded casts

Unneeded casts prevent the compiler from performing valuable checks.
This is especially true for function pointers.

Remove these casts, to prevent silently introducing bugs when a
variable's type might be changed in the future.

No change in generated code.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>