[SPARC64]: Fix section mismatch from kernel_map_range

Fix following warnings:
WARNING: vmlinux.o(.text+0x4f980): Section mismatch in reference from the function kernel_map_range() to the function .init.text:__alloc_bootmem()
WARNING: vmlinux.o(.text+0x4f9cc): Section mismatch in reference from the function kernel_map_range() to the function .init.text:__alloc_bootmem()

alloc_bootmem() is only used during early init and for any subsequent
call to kernel_map_range() the program logic avoid the call.
So annotate kernel_map_range() with __ref to tell modpost to
ignore the reference to a __init function.
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

arch/sparc64/mm/init.c

@@ -1010,7 +1010,8 @@ static struct linux_prom64_registers pall[MAX_BANKS] __initdata;
 static int pall_ents __initdata;
 
 #ifdef CONFIG_DEBUG_PAGEALLOC
-static unsigned long kernel_map_range(unsigned long pstart, unsigned long pend, pgprot_t prot)
+static unsigned long __ref kernel_map_range(unsigned long pstart,
+					    unsigned long pend, pgprot_t prot)
 {
 	unsigned long vstart = PAGE_OFFSET + pstart;
 	unsigned long vend = PAGE_OFFSET + pend;