powerpc: T1042: Remove macro CONFIG_PPC_T1042

Replace CONFIG_PPC_T1042 with ARCH_T1024 in Kconfig and clean up
existing macros.

Signed-off-by: York Sun <york.sun@nxp.com>
diff --git a/arch/powerpc/cpu/mpc85xx/Makefile b/arch/powerpc/cpu/mpc85xx/Makefile
index 6310a72..375a905 100644
--- a/arch/powerpc/cpu/mpc85xx/Makefile
+++ b/arch/powerpc/cpu/mpc85xx/Makefile
@@ -50,7 +50,7 @@
 obj-$(CONFIG_ARCH_B4420) += b4860_ids.o
 obj-$(CONFIG_ARCH_B4860) += b4860_ids.o
 obj-$(CONFIG_ARCH_T1040) += t1040_ids.o
-obj-$(CONFIG_PPC_T1042)	+= t1040_ids.o
+obj-$(CONFIG_ARCH_T1042)	+= t1040_ids.o
 obj-$(CONFIG_PPC_T1020)	+= t1040_ids.o
 obj-$(CONFIG_PPC_T1022)	+= t1040_ids.o
 obj-$(CONFIG_ARCH_T1023) += t1024_ids.o
@@ -93,7 +93,7 @@
 obj-$(CONFIG_ARCH_B4860) += b4860_serdes.o
 obj-$(CONFIG_ARCH_BSC9132) += bsc9132_serdes.o
 obj-$(CONFIG_ARCH_T1040) += t1040_serdes.o
-obj-$(CONFIG_PPC_T1042)	+= t1040_serdes.o
+obj-$(CONFIG_ARCH_T1042)	+= t1040_serdes.o
 obj-$(CONFIG_PPC_T1020)	+= t1040_serdes.o
 obj-$(CONFIG_PPC_T1022)	+= t1040_serdes.o
 obj-$(CONFIG_ARCH_T1023) += t1024_serdes.o