clk: mediatek: fix the PCIe MAC clock parent

The PCIe function doesn't work as the clock tree of MAC layer is wrong.
Hence fix the clock table.

Fixes: 3b5e7486 ("clk: mediatek: add clock support for MT7629 SoC")
Signed-off-by: Ryder Lee <ryder.lee@mediatek.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>