sh: Kill off unused flush_icache_user_range().

We use flush_cache_page() outright in copy_to_user_page(), and nothing
else needs it, so just kill it off. SH-5 still defines its own version,
but that too will go away in the same fashion once it converts over.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

arch/sh/include/cpu-sh4/cpu/cacheflush.h

@@ -25,8 +25,6 @@ void flush_cache_page(struct vm_area_struct *vma, unsigned long addr,
 		      unsigned long pfn);
 void flush_dcache_page(struct page *pg);
 void flush_icache_range(unsigned long start, unsigned long end);
-void flush_icache_user_range(struct vm_area_struct *vma, struct page *page,
-			     unsigned long addr, int len);
 
 #define flush_icache_page(vma,pg)		do { } while (0)