crypto: caam/qi2 - fix Chacha20 + Poly1305 self test failure

key buffer is not copied in chachapoly_setkey function,
results in wrong output for encryption/decryption operation.

fix this by memcpy the key in caam_ctx key arrary

Fixes: c10a5336 ("crypto: caam/qi2 - add support for Chacha20 + Poly1305")
Signed-off-by: Gaurav Jain <gaurav.jain@nxp.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>