On Ubuntu 21.10 (ppc64le) building `raid6test` with gcc (Ubuntu
11.2.0-7ubuntu2) 11.2.0 fails with the error below.

    gcc -I.. -I ../../../include -g -O2                      -I../../../arch/powerpc/include -DCONFIG_ALTIVEC -c -o vpermxor1.o vpermxor1.c
    vpermxor1.c: In function ‘raid6_vpermxor1_gen_syndrome_real’:
    vpermxor1.c:64:29: error: expected string literal before ‘VPERMXOR’
       64 |                         asm(VPERMXOR(%0,%1,%2,%3):"=v"(wq0):"v"(gf_high), "v"(gf_low), "v"(wq0));
          |                             ^~~~~~~~
    make: *** [Makefile:58: vpermxor1.o] Error 1

So, include the header `asm/ppc-opcode.h` defining this macro also when
not building the Linux kernel but only this too.

Cc: Matt Brown <redacted>
Signed-off-by: Paul Menzel <redacted>
---
 lib/raid6/vpermxor.uc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/raid6/vpermxor.uc b/lib/raid6/vpermxor.uc
index 10475dc423c1..1bfb127fbfe8 100644
--- a/lib/raid6/vpermxor.uc
+++ b/lib/raid6/vpermxor.uc

@@ -24,9 +24,9 @@
 #ifdef CONFIG_ALTIVEC
 
 #include <altivec.h>
+#include <asm/ppc-opcode.h>
 #ifdef __KERNEL__
 #include <asm/cputable.h>
-#include <asm/ppc-opcode.h>
 #include <asm/switch_to.h>
 #endif
 

-- 
2.34.1