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/include/asm/config_mpc85xx.h b/arch/powerpc/include/asm/config_mpc85xx.h
index 7a65caa..8efc805 100644
--- a/arch/powerpc/include/asm/config_mpc85xx.h
+++ b/arch/powerpc/include/asm/config_mpc85xx.h
@@ -679,7 +679,7 @@
 #define CONFIG_NUM_DDR_CONTROLLERS	1
 #endif
 
-#elif defined(CONFIG_ARCH_T1040) || defined(CONFIG_PPC_T1042) ||\
+#elif defined(CONFIG_ARCH_T1040) || defined(CONFIG_ARCH_T1042) ||\
 defined(CONFIG_PPC_T1020) || defined(CONFIG_PPC_T1022)
 #define CONFIG_E5500
 #define CONFIG_FSL_CORENET		/* Freescale CoreNet platform */
@@ -689,7 +689,7 @@
 #ifdef CONFIG_SYS_FSL_DDR4
 #define CONFIG_SYS_FSL_DDRC_GEN4
 #endif
-#if defined(CONFIG_ARCH_T1040) || defined(CONFIG_PPC_T1042)
+#if defined(CONFIG_ARCH_T1040) || defined(CONFIG_ARCH_T1042)
 #define CONFIG_MAX_CPUS			4
 #elif defined(CONFIG_PPC_T1020) || defined(CONFIG_PPC_T1022)
 #define CONFIG_MAX_CPUS			2