clk: meson-axg: add clocks required by pcie driver

Adding clocks for the pcie driver. Due to the ASIC design,
the pcie controller re-use part of the mipi clock logic,
so the mipi clock is also added.

Tested-by: Jianxin Qin <jianxin.qin@amlogic.com>
Signed-off-by: Yixun Lan <yixun.lan@amlogic.com>
[amended to remove unnecessary locales]
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>