crypto: powerpc/poly1305 - add depends on BROKEN for now

As discussed in the thread containing
https://lore.kernel.org/linux-crypto/20250510053308.GB505731@sol/, the
Power10-optimized Poly1305 code is currently not safe to call in softirq
context.  Disable it for now.  It can be re-enabled once it is fixed.

Fixes: ba8f862 ("crypto: poly1305-p10 - Glue code for optmized Poly1305 implementation for ppc64le")
Cc: stable@vger.kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Author: ebiggers

arch/powerpc/lib/crypto/Kconfig

@@ -10,6 +10,7 @@ config CRYPTO_CHACHA20_P10
 config CRYPTO_POLY1305_P10
 	tristate
 	depends on PPC64 && CPU_LITTLE_ENDIAN && VSX
+	depends on BROKEN # Needs to be fixed to work in softirq context
 	default CRYPTO_LIB_POLY1305
 	select CRYPTO_ARCH_HAVE_LIB_POLY1305
 	select CRYPTO_LIB_POLY1305_GENERIC