[POWERPC] Allow xmon to build on legacy iSeries

xmon still does not run on iSeries, but this allows us to build a combined
kernel that includes it.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/Kconfig.debug b/arch/powerpc/Kconfig.debug
index ff16063..5cce904 100644
--- a/arch/powerpc/Kconfig.debug
+++ b/arch/powerpc/Kconfig.debug
@@ -77,7 +77,7 @@
 
 config XMON
 	bool "Include xmon kernel debugger"
-	depends on DEBUGGER && !PPC_ISERIES
+	depends on DEBUGGER
 	help
 	  Include in-kernel hooks for the xmon kernel monitor/debugger.
 	  Unless you are intending to debug the kernel, say N here.