crypto: testmgr - Move crypto_simd_disabled_for_test out

As testmgr is part of cryptomgr which was designed to be unloadable
as a module, it shouldn't export any symbols for other crypto
modules to use as that would prevent it from being unloaded.  All
its functionality is meant to be accessed through notifiers.

The symbol crypto_simd_disabled_for_test was added to testmgr
which caused it to be pinned as a module if its users were also
loaded.  This patch moves it out of testmgr and into crypto/algapi.c
so cryptomgr can again be unloaded and replaced on demand.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>