pci: pcie_dw_rockchip: Drop the unused variable warning

pci: pcie_dw_rockchip: Drop the unused variable warning

Drop the unused variable warning below.

drivers/pci/pcie_dw_rockchip.c:161:6: warning: unused variable
'val' [-Wunused-variable]
  161 |  u32 val;
       |      ^~~
Cc: Patrick Wildt <[email protected]>
Cc: Neil Armstrong <[email protected]>
Cc: Kever Yang <[email protected]>
Reviewed-by: Neil Armstrong <[email protected]>
Reviewed-by: Patrick Wildt <[email protected]>
Signed-off-by: Anand Moon <[email protected]>
Reviewed-by: Kever Yang <[email protected]>