Platform: OLPC: Make olpc_dt_compatible_match() static __init

Addresses a kbuild warning:

  >> WARNING: vmlinux.o(.text+0x3b764): Section mismatch in reference from
              the function olpc_dt_compatible_match() to the function
              .init.text:olpc_dt_getproperty()
Signed-off-by: NLubomir Rintel <lkundrak@v3.sk>
Reported-by: Nkbuild test robot <lkp@intel.com>
Fixes: a7a9bacb (x86/platform/olpc: Use a correct version when making up a battery node)
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>

arch/x86/platform/olpc/olpc_dt.c

@@ -220,7 +220,7 @@ static u32 __init olpc_dt_get_board_revision(void)
 	return be32_to_cpu(rev);
 }
 
-int olpc_dt_compatible_match(phandle node, const char *compat)
+static int __init olpc_dt_compatible_match(phandle node, const char *compat)
 {
 	char buf[64], *p;
 	int plen, len;