usb: misc: brcmstb-usb-pinmap: Make sync_all_pins static

Fix the following sparse warning:

drivers/usb/misc/brcmstb-usb-pinmap.c:219:6: warning: symbol 'sync_all_pins' was not declared. Should it be static?

The sync_all_pins has only call site within brcmstb-usb-pinmap.c
It should be static

Fixes: 517c4c44b323 ("usb: Add driver to allow any GPIO to be used for 7211 USB signals")
Reported-by: Hulk Robot <[e-mail]>
Signed-off-by: Zou Wei <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/usb/misc/brcmstb-usb-pinmap.c

···
 	return 0;
 }
 
-void sync_all_pins(struct brcmstb_usb_pinmap_data *pdata)
+static void sync_all_pins(struct brcmstb_usb_pinmap_data *pdata)
 {
 	struct out_pin *pout;
 	struct in_pin *pin;