powerpc/fsl: Added aliased MSIIR register address to MSI node in dts

The MSIIR register for each MSI bank is aliased to a different
address. The MSI node reg property was updated to contain this
address:

e.g. reg = <0x41600 0x200 0x44140 4>;

The first region contains the address and length of the MSI
register set and the second region contains the address of
the aliased MSIIR register at 0x44140.

Signed-off-by: Diana CRACIUN <Diana.Craciun@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>