rework structure

hifive1-vp/riscv-bldc-forced-commutation/bsp/include/sifive/const.h

@@ -0,0 +1,18 @@
+// See LICENSE for license details.
+/* Derived from <linux/const.h> */
+
+#ifndef _SIFIVE_CONST_H
+#define _SIFIVE_CONST_H
+
+#ifdef __ASSEMBLER__
+#define _AC(X,Y)        X
+#define _AT(T,X)        X
+#else
+#define _AC(X,Y)        (X##Y)
+#define _AT(T,X)        ((T)(X))
+#endif /* !__ASSEMBLER__*/
+
+#define _BITUL(x)       (_AC(1,UL) << (x))
+#define _BITULL(x)      (_AC(1,ULL) << (x))
+
+#endif /* _SIFIVE_CONST_H */