serial: samsung: fix casting warning

port->membase is (unsigned char __iomem *), not (unsigned long *)
__set_bit() uses (unsigned long *) as the second argument.
Thus, casting (unsigned long *)(unsigned long) is necessary
to fix the following sparse warnings.

drivers/tty/serial/samsung.c:142:33: warning: cast removes address space of expression
drivers/tty/serial/samsung.c:161:33: warning: cast removes address space of expression
drivers/tty/serial/samsung.c:176:33: warning: cast removes address space of expression
drivers/tty/serial/samsung.c:526:40: warning: cast removes address space of expression
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/samsung.h

@@ -68,7 +68,8 @@ struct s3c24xx_uart_port {
 /* register access controls */
 
 #define portaddr(port, reg) ((port)->membase + (reg))
-#define portaddrl(port, reg) ((unsigned long *)((port)->membase + (reg)))
+#define portaddrl(port, reg) \
+	((unsigned long *)(unsigned long)((port)->membase + (reg)))
 
 #define rd_regb(port, reg) (__raw_readb(portaddr(port, reg)))
 #define rd_regl(port, reg) (__raw_readl(portaddr(port, reg)))