powerpc: Move FW feature probing out of pseries probe()

We move the function itself to pseries/firmware.c and call it along
with almost all other flat device-tree parsers from early_init_devtree()

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
[mpe: Move #ifdefs into the header by providing pseries_probe_fw_features()]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/kernel/prom.c

@@ -57,6 +57,7 @@
 #include <asm/fadump.h>
 #include <asm/debug.h>
 #include <asm/epapr_hcalls.h>
+#include <asm/firmware.h>
 
 #include <mm/mmu_decl.h>
 
@@ -755,6 +756,9 @@ void __init early_init_devtree(void *params)
 #endif
 	epapr_paravirt_early_init();
 
+	/* Now try to figure out if we are running on LPAR and so on */
+	pseries_probe_fw_features();
+
 	DBG(" <- early_init_devtree()\n");
 }