PCI: rockchip-host: Remove unused header includes

Clean up the driver by removing unnecessary header includes that are no
longer referenced after the recent refactoring.

Signed-off-by: Hans Zhang <18255117159@163.com>
[mani: commit message rewording]
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
Reviewed-by: Manivannan Sadhasivam <mani@kernel.org>
Acked-by: Shawn Lin <shawn.lin@rock-chips.com>
Link: https://patch.msgid.link/20250607160201.807043-4-18255117159@163.com