net: ethernet: mtk_eth_soc: use be32 type to store be32 values

net: ethernet: mtk_eth_soc: use be32 type to store be32 values

n_addr is used to store be32 values,
so a sparse-friendly array of be32 to store these values.

Flagged by sparse:
  .../mtk_ppe_debugfs.c:59:27: warning: incorrect type in assignment (different base types)
  .../mtk_ppe_debugfs.c:59:27:    expected unsigned int
  .../mtk_ppe_debugfs.c:59:27:    got restricted __be32 [usertype]
  .../mtk_ppe_debugfs.c:161:46: warning: cast to restricted __be16

No functional changes intended.
Compile tested only.

Signed-off-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20230401-mtk_eth_soc-sparse-v2-1-963becba3cb7@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>