The I2C and UARTS are clocked by the I/O clock, use its rate for these
devices.
Signed-off-by: NDavid Daney <ddaney@caviumnetworks.com>
Patchwork: http://patchwork.linux-mips.org/patch/1670/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>