powerpc: P4080: Remove macro CONFIG_PPC_P4080

Replace CONFIG_PPC_P4080 with ARCH_P4080 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 8f0a250..011aec6 100644
--- a/arch/powerpc/include/asm/config_mpc85xx.h
+++ b/arch/powerpc/include/asm/config_mpc85xx.h
@@ -378,7 +378,7 @@
 #define CONFIG_SYS_FSL_ERRATUM_A006261
 #define CONFIG_SYS_FSL_A004447_SVR_REV	0x20
 
-#elif defined(CONFIG_PPC_P4080) /* also supports P4040 */
+#elif defined(CONFIG_ARCH_P4080) /* also supports P4040 */
 #define CONFIG_SYS_FSL_QORIQ_CHASSIS1
 #define CONFIG_FSL_CORENET		/* Freescale CoreNet platform */
 #define CONFIG_MAX_CPUS			8