powerpc: P1023: Remove macro CONFIG_P1023

Replace CONFIG_P1023 with ARCH_P1023 in Kconfig and clean up existing
macros.

Signed-off-by: York Sun <york.sun@nxp.com>
diff --git a/drivers/net/fm/Makefile b/drivers/net/fm/Makefile
index 316fef4..05abbcf 100644
--- a/drivers/net/fm/Makefile
+++ b/drivers/net/fm/Makefile
@@ -18,7 +18,7 @@
 
 # SoC specific SERDES support
 obj-$(CONFIG_P1017)	+= p1023.o
-obj-$(CONFIG_P1023)	+= p1023.o
+obj-$(CONFIG_ARCH_P1023)	+= p1023.o
 # The P204x, P304x, and P5020 are the same
 obj-$(CONFIG_PPC_P2041) += p5020.o
 obj-$(CONFIG_PPC_P3041) += p5020.o