x86/platform: Avoid missing-prototype warnings for OLPC

There are two functions in the olpc platform that have no prototype:

arch/x86/platform/olpc/olpc_dt.c:237:13: error: no previous prototype for 'olpc_dt_fixup' [-Werror=missing-prototypes]
arch/x86/platform/olpc/olpc-xo1-pm.c:73:26: error: no previous prototype for 'xo1_do_sleep' [-Werror=missing-prototypes]

The first one should just be marked 'static' as there are no other
callers, while the second one is called from assembler and is
just a false-positive warning that can be silenced by adding a
prototype.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Link: https://lore.kernel.org/all/20230516193549.544673-21-arnd%40kernel.org

Author: arndb

arch/x86/platform/olpc/olpc_dt.c

@@ -234,7 +234,7 @@ static int __init olpc_dt_compatible_match(phandle node, const char *compat)
 	return 0;
 }
 
-void __init olpc_dt_fixup(void)
+static void __init olpc_dt_fixup(void)
 {
 	phandle node;
 	u32 board_rev;

include/linux/olpc-ec.h

@@ -56,6 +56,8 @@ extern int olpc_ec_sci_query(u16 *sci_value);
 
 extern bool olpc_ec_wakeup_available(void);
 
+asmlinkage int xo1_do_sleep(u8 sleep_state);
+
 #else
 
 static inline int olpc_ec_cmd(u8 cmd, u8 *inbuf, size_t inlen, u8 *outbuf,