ssb: pick SoC invariants code from MIPS BCM47xx arch

There is code in ssb fetching "invariants" that is basically a set of
board specific data. Every host requires its own implementation of
reading function. In ssb we have support for PCI, PCMCIA & SDIO.
For some (historical?) reason code reading "invariants" for SoC was
placed in arch code and provided by a callback. This is not needed
nowadays, so lets move that into ssb. This way we keep all "invariants"
functions in a single module making code cleaner.

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
diff --git a/drivers/ssb/ssb_private.h b/drivers/ssb/ssb_private.h
index 15bfd5c..c2f5d39 100644
--- a/drivers/ssb/ssb_private.h
+++ b/drivers/ssb/ssb_private.h
@@ -163,6 +163,9 @@
 
 #ifdef CONFIG_SSB_HOST_SOC
 extern const struct ssb_bus_ops ssb_host_soc_ops;
+
+extern int ssb_host_soc_get_invariants(struct ssb_bus *bus,
+				       struct ssb_init_invariants *iv);
 #endif
 
 /* scan.c */