powerpc: update tls macros inline asm clobbers

This was causing a compile error for powerpc64 toolchain
because r3 was both listed as clobbered and as output
in inline asm.

Signed-off-by: Yann Sionneau <yann@sionneau.net>

test/tls/tls-macros-powerpc.h

@@ -1,5 +1,5 @@
 #define __TLS_CALL_CLOBBERS						\
-	"0", "3", "4", "5", "6", "7", "8", "9", "10", "11", "12",	\
+	"0", "4", "5", "6", "7", "8", "9", "10", "11", "12",	\
 	"lr", "ctr", "cr0", "cr1", "cr5", "cr6", "cr7"
 
 /* PowerPC32 Local Exec TLS access.  */