fs/squashfs: correct aarch64 conditional

BR_aarch64 is not defined. it seems should be BR2_aarch64

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

fs/squashfs/Config.in

@@ -114,7 +114,7 @@ config BR2_TARGET_ROOTFS_SQUASHFS_COMP_OPTS
 	default "-Xcompression-level 9" if BR2_TARGET_ROOTFS_SQUASHFS4_GZIP
 	default "-Xcompression-level 9" if BR2_TARGET_ROOTFS_SQUASHFS4_LZO
 	default "-Xhc" if BR2_TARGET_ROOTFS_SQUASHFS4_LZ4
-	default "-Xbcj arm,armthumb" if BR2_TARGET_ROOTFS_SQUASHFS4_XZ && (BR2_arm || BR_aarch64)
+	default "-Xbcj arm,armthumb" if BR2_TARGET_ROOTFS_SQUASHFS4_XZ && (BR2_arm || BR2_aarch64)
 	default "-Xbcj powerpc" if BR2_TARGET_ROOTFS_SQUASHFS4_XZ && (BR2_powerpc || BR2_powerpc64)
 	default "-Xbcj sparc" if BR2_TARGET_ROOTFS_SQUASHFS4_XZ && (BR2_sparc || BR2_sparc64)
 	default "-Xbcj x86" if BR2_TARGET_ROOTFS_SQUASHFS4_XZ && (BR2_i386 || BR2_x86_64)