crypto: aesni - fix build on x86 (32bit)

It seems commit d764593a "crypto: aesni - AVX and AVX2 version of AESNI-GCM
encode and decode" breaks a build on x86_32 since it's designed only for
x86_64. This patch makes a compilation unit conditional to CONFIG_64BIT and
functions usage to CONFIG_X86_64.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/arch/x86/crypto/aesni-intel_glue.c b/arch/x86/crypto/aesni-intel_glue.c
index 3ae311d..948ad0e 100644
--- a/arch/x86/crypto/aesni-intel_glue.c
+++ b/arch/x86/crypto/aesni-intel_glue.c
@@ -1473,6 +1473,7 @@
 
 	if (!x86_match_cpu(aesni_cpu_id))
 		return -ENODEV;
+#ifdef CONFIG_X86_64
 #ifdef CONFIG_AS_AVX2
 	if (boot_cpu_has(X86_FEATURE_AVX2)) {
 		pr_info("AVX2 version of gcm_enc/dec engaged.\n");
@@ -1492,6 +1493,7 @@
 		aesni_gcm_enc_tfm = aesni_gcm_enc;
 		aesni_gcm_dec_tfm = aesni_gcm_dec;
 	}
+#endif
 
 	err = crypto_fpu_init();
 	if (err)