serial: clean up uart_info

Since commit ebd2c8f6d2ec ("serial: kill off uart_info") has
removed uart_info, the uart_info declaration looks lonely,
let it go.

Signed-off-by: Yanteng Si <[e-mail]>
Reviewed-by: Andy Shevchenko <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

include/linux/platform_data/sa11x0-serial.h

···
 #define SA11X0_SERIAL_H
 
 struct uart_port;
-struct uart_info;
 
 /*
  * This is a temporary structure for registering these