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/kernel/udbg.c b/arch/powerpc/kernel/udbg.c
index 9d3fdcd..a158375 100644
--- a/arch/powerpc/kernel/udbg.c
+++ b/arch/powerpc/kernel/udbg.c
@@ -50,7 +50,7 @@
 	udbg_init_debug_beat();
 #elif defined(CONFIG_PPC_EARLY_DEBUG_PAS_REALMODE)
 	udbg_init_pas_realmode();
-#elif defined(CONFIG_BOOTX_TEXT)
+#elif defined(CONFIG_PPC_EARLY_DEBUG_BOOTX)
 	udbg_init_btext();
 #elif defined(CONFIG_PPC_EARLY_DEBUG_44x)
 	/* PPC44x debug */