serial: 8250: Remove unused define

HIGH_BITS_OFFSET is only used in the serial core; remove from 8250-
specific header.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/8250/8250.h

@@ -84,7 +84,6 @@ struct serial8250_config {
 #define UART_BUG_THRE	(1 << 3)	/* UART has buggy THRE reassertion */
 #define UART_BUG_PARITY	(1 << 4)	/* UART mishandles parity if FIFO enabled */
 
-#define HIGH_BITS_OFFSET ((sizeof(long)-sizeof(int))*8)
 
 #ifdef CONFIG_SERIAL_8250_SHARE_IRQ
 #define SERIAL8250_SHARE_IRQS 1