MIPS: Octeon: Serial port fixes for OCTEON simulator.

For the simulator, fake a slow clock to get fast output.

In prom_putchar we have to mask the value so the simulator doesn't
ASSERT when printing non-ASCII characters.

Signed-off-by: David Daney <ddaney@caviumnetworks.com>
To: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/1255/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/cavium-octeon/setup.c b/arch/mips/cavium-octeon/setup.c
index 44cb20c..d1b5ffa 100644
--- a/arch/mips/cavium-octeon/setup.c
+++ b/arch/mips/cavium-octeon/setup.c
@@ -702,7 +702,7 @@
 	} while ((lsrval & 0x20) == 0);
 
 	/* Write the byte */
-	cvmx_write_csr(CVMX_MIO_UARTX_THR(octeon_uart), c);
+	cvmx_write_csr(CVMX_MIO_UARTX_THR(octeon_uart), c & 0xffull);
 	return 1;
 }