[POWERPC] Small cleanup of EFIKA platform

The efika platform used three files efika-pci.c efika-setup.c and
a 2 line efika.h to link the two. The total of code in those is
really not much and therefore, I think they're better merged
in a single file.

There is absolutely _no_code_change_ at all, just merged the files.

Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Paul Mackerras <paulus@samba.org>