powerpc: P3041: Remove macro CONFIG_PPC_P3041

Replace CONFIG_PPC_P3041 with ARCH_P3041 in Kconfig and clean up
existing macros.

Signed-off-by: York Sun <york.sun@nxp.com>
diff --git a/arch/powerpc/cpu/mpc85xx/Kconfig b/arch/powerpc/cpu/mpc85xx/Kconfig
index 0ddb7c5..d8bc1d0 100644
--- a/arch/powerpc/cpu/mpc85xx/Kconfig
+++ b/arch/powerpc/cpu/mpc85xx/Kconfig
@@ -41,6 +41,7 @@
 config TARGET_P3041DS
 	bool "Support P3041DS"
 	select PHYS_64BIT
+	select ARCH_P3041
 
 config TARGET_P4080DS
 	bool "Support P4080DS"
@@ -316,6 +317,9 @@
 config ARCH_P2041
 	bool
 
+config ARCH_P3041
+	bool
+
 source "board/freescale/b4860qds/Kconfig"
 source "board/freescale/bsc9131rdb/Kconfig"
 source "board/freescale/bsc9132qds/Kconfig"