crypto: sl3516 - Add dependency on ARCH_GEMINI

The Storlink SL3516 crypto engine is only present on Storlink
Semiconductor/Storm Semiconductor/Cortina Systems Gemini SoCs.
Hence add a dependency on ARCH_GEMINI, to prevent asking the user about
this driver when configuring a kernel without Gemini support.

While at it, group the dependencies.

Fixes: 46c5338d ("crypto: sl3516 - Add sl3516 crypto engine")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>