staging: speakup: fix type mismatch warnings

Compiling speakup driver with sparse produces following warning:

drivers/staging/speakup/serialio.c:22:9: warning: incorrect type in
initializer (different base types)
drivers/staging/speakup/serialio.c:22:9:    expected unsigned int
[unsigned] flags
drivers/staging/speakup/serialio.c:22:9:    got restricted upf_t

This patch fixes it.
Signed-off-by: Okash Khawaja <okash.khawaja@gmail.com>
Acked-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/speakup/serialio.h

@@ -6,6 +6,7 @@
 #ifndef __sparc__
 #include <linux/serial.h>
 #endif
+#include <linux/serial_core.h>
 
 /*
  * this is cut&paste from 8250.h. Get rid of the structure, the definitions
@@ -16,7 +17,7 @@ struct old_serial_port {
 	unsigned int baud_base;
 	unsigned int port;
 	unsigned int irq;
-	unsigned int flags; /* unused */
+	upf_t flags; /* unused */
 };
 
 /* countdown values for serial timeouts in us */