remove unused header, which breaks the toolchain building

Signed-off-by: Waldemar Brodkorb <wbx@openadk.org>

---
 libgcc/config/m68k/linux-atomic.c |    1 -
 1 file changed, 1 deletion(-)

--- a/libgcc/config/m68k/linux-atomic.c
+++ b/libgcc/config/m68k/linux-atomic.c
@@ -33,7 +33,6 @@
    using the kernel helper defined below.  There is no support for
    64-bit operations yet.  */
 
-#include <asm/unistd.h>
 #include <stdbool.h>
 
 #ifndef __NR_atomic_cmpxchg_32