powerpc: Add a configuration option for early BootX/OpenFirmware debug

Signed-off-by: Alistair Popple <alistair@popple.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/Kconfig.debug b/arch/powerpc/Kconfig.debug
index 863d877..d86875f 100644
--- a/arch/powerpc/Kconfig.debug
+++ b/arch/powerpc/Kconfig.debug
@@ -147,6 +147,13 @@
 	  enable debugging for the wrong type of machine your kernel
 	  _will not boot_.
 
+config PPC_EARLY_DEBUG_BOOTX
+	bool "BootX or OpenFirmware"
+	depends on BOOTX_TEXT
+	help
+	  Select this to enable early debugging for a machine using BootX
+	  or OpenFirmware.
+
 config PPC_EARLY_DEBUG_LPAR
 	bool "LPAR HV Console"
 	depends on PPC_PSERIES