MIPS: Octeon: Use I/O clock rate for calculations.

The I2C and UARTS are clocked by the I/O clock, use its rate for these
devices.

Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Patchwork: http://patchwork.linux-mips.org/patch/1670/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/cavium-octeon/serial.c b/arch/mips/cavium-octeon/serial.c
index 12dbf53..057f0ae 100644
--- a/arch/mips/cavium-octeon/serial.c
+++ b/arch/mips/cavium-octeon/serial.c
@@ -66,7 +66,7 @@
 		/* Make simulator output fast*/
 		p->uartclk = 115200 * 16;
 	else
-		p->uartclk = mips_hpt_frequency;
+		p->uartclk = octeon_get_io_clock_rate();
 	p->serial_in = octeon_serial_in;
 	p->serial_out = octeon_serial_out;
 }