Rename pcie pinctrl definition to fix the following dtbs_check error
for mt8370-genio-510-evk and mt8390-genio-700-evk devicetree files:
```
pinctrl@10005000: 'pcie-default' does not match any of the regexes:
'-pins$', 'pinctrl-[0-9]+'
```
Signed-off-by: Louis-Alexis Eyraud <louisalexis.eyraud@xxxxxxxxxxxxx>