Do not build P10-specific AES-GCM assembler on AIX

Reviewed-by: Paul Dale <pauli@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/19865)

(cherry picked from commit 5c92ac52c282dbcb07e3880c2edd3a1bce452396)

crypto/modes/build.info

@@ -32,7 +32,10 @@ IF[{- !$disabled{asm} -}]
   $MODESASM_parisc20_64=$MODESASM_parisc11
   $MODESDEF_parisc20_64=$MODESDEF_parisc11
 
-  $MODESASM_ppc32=ghashp8-ppc.s aes-gcm-ppc.s
+  $MODESASM_ppc32=ghashp8-ppc.s
+  IF[{- $target{sys_id} ne "AIX" -}]
+    $MODESASM_ppc32=ghashp8-ppc.s aes-gcm-ppc.s
+  ENDIF
   $MODESDEF_ppc32=
   $MODESASM_ppc64=$MODESASM_ppc32
   $MODESDEF_ppc64=$MODESDEF_ppc32

include/crypto/aes_platform.h

@@ -74,18 +74,20 @@ void AES_xts_decrypt(const unsigned char *inp, unsigned char *out, size_t len,
 #   define HWAES_ctr32_encrypt_blocks aes_p8_ctr32_encrypt_blocks
 #   define HWAES_xts_encrypt aes_p8_xts_encrypt
 #   define HWAES_xts_decrypt aes_p8_xts_decrypt
-#   define PPC_AES_GCM_CAPABLE (OPENSSL_ppccap_P & PPC_MADD300)
-#   define AES_GCM_ENC_BYTES 128
-#   define AES_GCM_DEC_BYTES 128
+#   ifndef OPENSSL_SYS_AIX
+#    define PPC_AES_GCM_CAPABLE (OPENSSL_ppccap_P & PPC_MADD300)
+#    define AES_GCM_ENC_BYTES 128
+#    define AES_GCM_DEC_BYTES 128
 size_t ppc_aes_gcm_encrypt(const unsigned char *in, unsigned char *out,
                            size_t len, const void *key, unsigned char ivec[16],
                            u64 *Xi);
 size_t ppc_aes_gcm_decrypt(const unsigned char *in, unsigned char *out,
                            size_t len, const void *key, unsigned char ivec[16],
                            u64 *Xi);
-#   define AES_GCM_ASM_PPC(gctx) ((gctx)->ctr==aes_p8_ctr32_encrypt_blocks && \
-                                 (gctx)->gcm.funcs.ghash==gcm_ghash_p8)
+#    define AES_GCM_ASM_PPC(gctx) ((gctx)->ctr==aes_p8_ctr32_encrypt_blocks && \
+                                   (gctx)->gcm.funcs.ghash==gcm_ghash_p8)
 void gcm_ghash_p8(u64 Xi[2],const u128 Htable[16],const u8 *inp, size_t len);
+#   endif /* OPENSSL_SYS_AIX */
 #  endif /* PPC */
 
 #  if (defined(__arm__) || defined(__arm) || defined(__aarch64__))