powerpc: Merge rtas.c into arch/powerpc/kernel

This splits arch/ppc64/kernel/rtas.c into arch/powerpc/kernel/rtas.c,
which contains generic RTAS functions useful on any CHRP platform,
and arch/powerpc/platforms/pseries/rtas-fw.[ch], which contain
some pSeries-specific firmware flashing bits.  The parts of rtas.c
that are to do with pSeries-specific error logging are protected
by a new CONFIG_RTAS_ERROR_LOGGING symbol.  The inclusion of rtas.o
is controlled by the CONFIG_PPC_RTAS symbol, and the relevant
platforms select that.

Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 9f279e0..ce5100c 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -276,6 +276,8 @@
 	depends on PPC_MULTIPLATFORM && PPC64
 	bool "  IBM pSeries & new (POWER5-based) iSeries"
 	select PPC_I8259
+	select PPC_RTAS
+	select RTAS_ERROR_LOGGING
 	default y
 
 config PPC_CHRP
@@ -283,6 +285,7 @@
 	depends on PPC_MULTIPLATFORM && PPC32
 	select PPC_I8259
 	select PPC_INDIRECT_PCI
+	select PPC_RTAS
 	default y
 
 config PPC_PMAC
@@ -317,6 +320,7 @@
 config PPC_BPA
 	bool "  Broadband Processor Architecture"
 	depends on PPC_MULTIPLATFORM && PPC64
+	select PPC_RTAS
 
 config PPC_OF
 	bool
@@ -338,6 +342,15 @@
 	bool
 	default y
 
+config PPC_RTAS
+	bool
+	default n
+
+config RTAS_ERROR_LOGGING
+	bool
+	depends on PPC_RTAS
+	default n
+
 config MPIC_BROKEN_U3
 	bool
 	depends on PPC_MAPLE