arm64: Convert empty flush_cache_{mm,page} functions to static inline

These functions are empty, just make them static inline in the header.
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

arch/arm64/include/asm/cacheflush.h

@@ -70,13 +70,20 @@
  *		- size   - region size
  */
 extern void flush_cache_all(void);
-extern void flush_cache_mm(struct mm_struct *mm);
 extern void flush_cache_range(struct vm_area_struct *vma, unsigned long start, unsigned long end);
-extern void flush_cache_page(struct vm_area_struct *vma, unsigned long user_addr, unsigned long pfn);
 extern void flush_icache_range(unsigned long start, unsigned long end);
 extern void __flush_dcache_area(void *addr, size_t len);
 extern void __flush_cache_user_range(unsigned long start, unsigned long end);
 
+static inline void flush_cache_mm(struct mm_struct *mm)
+{
+}
+
+static inline void flush_cache_page(struct vm_area_struct *vma,
+				    unsigned long user_addr, unsigned long pfn)
+{
+}
+
 /*
  * Copy user data from/to a page which is mapped into a different
  * processes address space.  Really, we want to allow our "user

arch/arm64/mm/flush.c

@@ -27,10 +27,6 @@
 
 #include "mm.h"
 
-void flush_cache_mm(struct mm_struct *mm)
-{
-}
-
 void flush_cache_range(struct vm_area_struct *vma, unsigned long start,
 		       unsigned long end)
 {
@@ -38,11 +34,6 @@ void flush_cache_range(struct vm_area_struct *vma, unsigned long start,
 		__flush_icache_all();
 }
 
-void flush_cache_page(struct vm_area_struct *vma, unsigned long user_addr,
-		      unsigned long pfn)
-{
-}
-
 static void flush_ptrace_access(struct vm_area_struct *vma, struct page *page,
 				unsigned long uaddr, void *kaddr,
 				unsigned long len)