Rename __attribute__((packed)) --> __packed

Also unify __attribute__ ((..)) to __attribute__((..)) and
handle ((__packed__)) like ((packed))

Change-Id: Ie60a51c3fa92b5009724a5b7c2932e361bf3490c
Signed-off-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Reviewed-on: https://review.coreboot.org/15921
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

util/cbfstool/lz4/lib/xxhash.c

@@ -146,7 +146,7 @@ static U64 XXH_read64(const void* memPtr) { return *(const U64*) memPtr; }
 
 /* __pack instructions are safer, but compiler specific, hence potentially problematic for some compilers */
 /* currently only defined for gcc and icc */
-typedef union { U32 u32; U64 u64; } __attribute__((packed)) unalign;
+typedef union { U32 u32; U64 u64; } __packed unalign;
 
 static U32 XXH_read32(const void* ptr) { return ((const unalign*)ptr)->u32; }
 static U64 XXH_read64(const void* ptr) { return ((const unalign*)ptr)->u64; }