PCI: mediatek-gen3: Fix inconsistent indentation

PCI: mediatek-gen3: Fix inconsistent indentation

Fix the following inconsistent indentation warning:

  drivers/pci/controller/pcie-mediatek-gen3.c:922 mtk_pcie_parse_port() warn: inconsistent indenting

Found using Smatch.  No functional changes intended.

Signed-off-by: Charles Han <hanchunchao@inspur.com>
Link: https://lore.kernel.org/r/20250305070022.4668-1-hanchunchao@inspur.com
[kwilczynski: commit log, refactor if-statement around num_lanes to
make it more readable, wrap overly long lines to fit 80 colums]
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>