xtensa: clean up optional XCHAL_* definitions

Simplify users of XCHAL_HAVE_EXTERN_REGS and XCHAL_HAVE_VECBASE and
always define them as 0 if they're not defined in the variant/core.h
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

arch/xtensa/include/asm/core.h

@@ -10,10 +10,18 @@
 #define XCHAL_HAVE_EXCLUSIVE 0
 #endif
 
+#ifndef XCHAL_HAVE_EXTERN_REGS
+#define XCHAL_HAVE_EXTERN_REGS 0
+#endif
+
 #ifndef XCHAL_HAVE_MPU
 #define XCHAL_HAVE_MPU 0
 #endif
 
+#ifndef XCHAL_HAVE_VECBASE
+#define XCHAL_HAVE_VECBASE 0
+#endif
+
 #ifndef XCHAL_SPANNING_WAY
 #define XCHAL_SPANNING_WAY 0
 #endif

arch/xtensa/include/asm/processor.h

@@ -237,10 +237,6 @@ extern unsigned long get_wchan(struct task_struct *p);
 	 v; \
 	 })
 
-#ifndef XCHAL_HAVE_EXTERN_REGS
-#define XCHAL_HAVE_EXTERN_REGS 0
-#endif
-
 #if XCHAL_HAVE_EXTERN_REGS
 
 static inline void set_er(unsigned long value, unsigned long addr)

arch/xtensa/include/asm/vectors.h

@@ -40,7 +40,7 @@
 #define VECBASE_VADDR			_vecbase
 #endif
 
-#if defined(XCHAL_HAVE_VECBASE) && XCHAL_HAVE_VECBASE
+#if XCHAL_HAVE_VECBASE
 
 #define VECTOR_VADDR(offset)		(VECBASE_VADDR + offset)