security/cryptopp: enable SIMD by default on powerpc and powerpc64

Upstream can now check at runtime for SIMD availaibility. Merge upstream commits https://github.com/weidai11/cryptopp/commit/91173a287e668f7ce7e5086789b8db2300a159b1 and https://github.com/weidai11/cryptopp/commit/21a40abc5ceeb0ccf6577a444f1b4c19fa6379c6 to implement it.

Local patch is used because upstream patch doesn't apply.

Remove -maltivec and -mvsx, upstream now properly sets those flags on their own.