rk3368: iommu: fix 32bit iommu work error in 64bit kernel

rk3368: iommu: fix 32bit iommu work error in 64bit kernel

unsigned long has 8bytes in 64bit kernel,Maybach iommu each entry
both dte and pte has 4bytes,so we can not use unsigned long type
to define the entry address,otherwise,wrong page table will be set up,
that will cause page fault.So,replace unsigned long with unsigned int to
define the entry address

Signed-off-by: Simon <xxm@rock-chips.com>