powerpc: P1011: Remove macro CONFIG_P1011

Replace CONFIG_P1011 with ARCH_P1011 in Kconfig. P1011RDB seems to be in
scrapyard though.

Signed-off-by: York Sun <york.sun@nxp.com>
diff --git a/arch/powerpc/cpu/mpc85xx/Kconfig b/arch/powerpc/cpu/mpc85xx/Kconfig
index 0c498d8..d0c57a1 100644
--- a/arch/powerpc/cpu/mpc85xx/Kconfig
+++ b/arch/powerpc/cpu/mpc85xx/Kconfig
@@ -241,6 +241,9 @@
 config ARCH_P1010
 	bool
 
+config ARCH_P1011
+	bool
+
 config ARCH_P1022
 	bool