drm/bridge: make a const array static, makes object smaller

Don't populate the const array frs_limits on the stack but instead make
it static. Makes the object code smaller by 128 bytes:

Before:
   text    data     bss     dec     hex filename
  24845    7440      64   32349    7e5d ./drivers/gpu/drm/bridge/tc358768.o

After:
   text    data     bss     dec     hex filename
  24749    7408      64   32221    7ddd ./drivers/gpu/drm/bridge/tc358768.o

(gcc version 10.2.0)

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>