x86: highmem: Remove leftover function prototypes

-RT replaces kmap_atomic* functions with macros, but we kept the
 function prototypes around. Remove them.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

arch/x86/include/asm/highmem.h

@@ -69,14 +69,6 @@ void __kunmap_atomic(void *kvaddr, enum km_type type);
 void *__kmap_atomic_pfn(unsigned long pfn, enum km_type type);
 struct page *__kmap_atomic_to_page(void *ptr);
 
-void kunmap(struct page *page);
-void *kmap_atomic_prot(struct page *page, enum km_type type, pgprot_t prot);
-void *kmap_atomic(struct page *page, enum km_type type);
-void kunmap_atomic(void *kvaddr, enum km_type type);
-void *kmap_atomic_pfn(unsigned long pfn, enum km_type type);
-void *kmap_atomic_prot_pfn(unsigned long pfn, enum km_type type, pgprot_t prot);
-struct page *kmap_atomic_to_page(void *ptr);
-
 #ifndef CONFIG_PARAVIRT
 #define kmap_atomic_pte(page, type)		kmap_atomic(page, type)
 #define kmap_atomic_pte_direct(page, type)	kmap_atomic_direct(page, type)