crypto: ccp - Constify 'dev_vdata' member

crypto: ccp - Constify 'dev_vdata' member

sp_device->dev_vdata points to only const data (see 'static const struct
sp_dev_vdata dev_vdata'), so can be made pointer to const for code
safety.

Update also sp_get_acpi_version() function which returns this pointer to
'pointer to const' for code readability, even though it is not needed.

On the other hand, do not touch similar function sp_get_of_version()
because it will be immediately removed in next patches.

Acked-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>