I didn't explain well, There is a CFE command 'show devtree' here's the
relevant bits (I Hope)

This is much simple than I expected.

[CFE ]CFE> show devtree
[/]
 | #interrupt-cells                 val   0x00000002
 | #address-cells                   val   0x00000002
 | #size-cells                      val   0x00000002

...[snip]...

   [sdc@fc000000]
    | name                          str   'sdc'
    | device_type                   str   'sdc'
    | #address-cells                val   0x00000001
    | #size-cells                   val   0x00000001
    | compatible                    str   '1682m-sdc' 'pasemi,pwrficient-sdc'
'pasemi,sdc'
    | reg                           cell  00000000 FC000000 00000000 00800000

...[snip]...

      [rng@fc105000]
       | name                       str   'rng'
       | device_type                str   'rng'
       | compatible                 str   '1682m-rng' 'pasemi,pwrficient-rng'
'pasemi,rng'
       | reg                        cell  FC105000 00001000

Device tree provided by CFE has the size. I will send another patch
which uses devm_ioremap_resource().

Appreciate your help. Thank you :).