powerpc/configs: Drop no longer needed CONFIG_CRYPTO_NULL in g5 / c2k

Since commit 3491244c ("crypto: echainiv - Set Kconfig default to
m") we no longer need to set CONFIG_CRYPTO_NULL in our defconfigs.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/configs/c2k_defconfig

@@ -389,7 +389,6 @@ CONFIG_SECURITY_NETWORK=y
 CONFIG_SECURITY_SELINUX=y
 CONFIG_SECURITY_SELINUX_BOOTPARAM=y
 CONFIG_SECURITY_SELINUX_DISABLE=y
-CONFIG_CRYPTO_NULL=m
 CONFIG_CRYPTO_HMAC=y
 CONFIG_CRYPTO_MICHAEL_MIC=m
 CONFIG_CRYPTO_SHA1=y

arch/powerpc/configs/g5_defconfig

@@ -258,7 +258,6 @@ CONFIG_DEBUG_MUTEXES=y
 CONFIG_LATENCYTOP=y
 CONFIG_BOOTX_TEXT=y
 CONFIG_PPC_EARLY_DEBUG=y
-CONFIG_CRYPTO_NULL=m
 CONFIG_CRYPTO_TEST=m
 CONFIG_CRYPTO_PCBC=m
 CONFIG_CRYPTO_HMAC=y