tools uapi: fix Alpha support

Cc: stable@vger.kernel.org # v4.18+
Signed-off-by: Bob Tracy <rct@frus.com>
Signed-off-by: Matt Turner <mattst88@gmail.com>

tools/include/uapi/asm/bitsperlong.h

@@ -15,6 +15,8 @@
 #include "../../arch/ia64/include/uapi/asm/bitsperlong.h"
 #elif defined(__riscv)
 #include "../../arch/riscv/include/uapi/asm/bitsperlong.h"
+#elif defined(__alpha__)
+#include "../../arch/alpha/include/uapi/asm/bitsperlong.h"
 #else
 #include <asm-generic/bitsperlong.h>
 #endif