powerpc: P5020: Remove macro CONFIG_PPC_P5020

Replace CONFIG_PPC_P5020 with ARCH_P5020 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 011aec6..496b845 100644
--- a/arch/powerpc/include/asm/config_mpc85xx.h
+++ b/arch/powerpc/include/asm/config_mpc85xx.h
@@ -429,7 +429,7 @@
 #define CONFIG_SYS_FSL_ERRATUM_A007075
 #define CONFIG_SYS_FSL_A004447_SVR_REV	0x20
 
-#elif defined(CONFIG_PPC_P5020) /* also supports P5010 */
+#elif defined(CONFIG_ARCH_P5020) /* also supports P5010 */
 #define CONFIG_SYS_PPC64		/* 64-bit core */
 #define CONFIG_SYS_FSL_QORIQ_CHASSIS1
 #define CONFIG_FSL_CORENET		/* Freescale CoreNet platform */
diff --git a/arch/powerpc/include/asm/fsl_secure_boot.h b/arch/powerpc/include/asm/fsl_secure_boot.h
index 38b666c..47c3d98 100644
--- a/arch/powerpc/include/asm/fsl_secure_boot.h
+++ b/arch/powerpc/include/asm/fsl_secure_boot.h
@@ -60,7 +60,7 @@
 
 #if defined(CONFIG_ARCH_P3041)	||	\
 	defined(CONFIG_ARCH_P4080) ||	\
-	defined(CONFIG_PPC_P5020) ||	\
+	defined(CONFIG_ARCH_P5020) ||	\
 	defined(CONFIG_PPC_P5040) ||	\
 	defined(CONFIG_ARCH_P2041)
 	#define	CONFIG_FSL_TRUST_ARCH_v1
diff --git a/arch/powerpc/include/asm/immap_85xx.h b/arch/powerpc/include/asm/immap_85xx.h
index 83f8b8f..759671a 100644
--- a/arch/powerpc/include/asm/immap_85xx.h
+++ b/arch/powerpc/include/asm/immap_85xx.h
@@ -1857,7 +1857,7 @@
 #define FSL_CORENET_RCWSR11_EC2_USB2			0x00100000
 #endif
 #if defined(CONFIG_ARCH_P2041) || \
-	defined(CONFIG_ARCH_P3041) || defined(CONFIG_PPC_P5020)
+	defined(CONFIG_ARCH_P3041) || defined(CONFIG_ARCH_P5020)
 #define FSL_CORENET_RCWSR11_EC1_FM1_DTSEC4_RGMII	0x00000000
 #define FSL_CORENET_RCWSR11_EC1_FM1_DTSEC4_MII		0x00800000
 #define FSL_CORENET_RCWSR11_EC1_FM1_DTSEC4_NONE		0x00c00000