clk: socfpga: agilex: Remove unused variable 'cntr_mux'

clk: socfpga: agilex: Remove unused variable 'cntr_mux'

drivers/clk/socfpga/clk-agilex.c:24:37: warning: ‘cntr_mux’ defined but not used [-Wunused-const-variable=]
 static const struct clk_parent_data cntr_mux[] = {
                                     ^~~~~~~~

There is no caller in tree, so can remove it.

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Link: https://lore.kernel.org/r/20200915020950.4688-1-yuehaibing@huawei.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>