MIPS: JZ4740: replace use of jz4740_clock_bdata

Replace uses of the jz4740_clock_bdata struct with calls to clk_get_rate
for the appropriate clock. This is in preparation for migrating the
clocks towards common clock framework & devicetree.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: linux-mips@linux-mips.org
Cc: Deng-Cheng Zhu <dengcheng.zhu@imgtec.com>
Cc: linux-kernel@vger.kernel.org
Cc: Apelete Seketeli <apelete@seketeli.net>
Patchwork: https://patchwork.linux-mips.org/patch/10149/


Signed-off-by: Ralf Baechle <ralf@linux-mips.org>