linux-phytec-ti

powerpc/pseries: Drop always true CONFIG_PSERIES_MSI

Now that pseries selects PCI_MSI && PCI, EEH will always be true, and
therefore CONFIG_PSERIES_MSI will always be true. So drop it, and move
msi.o to obj-y.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>