powerpc: P1025: Remove macro CONFIG_P1025

Replace CONFIG_P1025 with ARCH_P1025 in Kconfig and clean up
existing macros.

Signed-off-by: York Sun <york.sun@nxp.com>
diff --git a/arch/powerpc/cpu/mpc85xx/speed.c b/arch/powerpc/cpu/mpc85xx/speed.c
index 8155620..38a28a8 100644
--- a/arch/powerpc/cpu/mpc85xx/speed.c
+++ b/arch/powerpc/cpu/mpc85xx/speed.c
@@ -596,7 +596,7 @@
 #endif
 
 #ifdef CONFIG_QE
-#if defined(CONFIG_ARCH_P1021) || defined(CONFIG_P1025)
+#if defined(CONFIG_ARCH_P1021) || defined(CONFIG_ARCH_P1025)
 	sys_info->freq_qe =  sys_info->freq_systembus;
 #else
 	qe_ratio = ((gur->porpllsr) & MPC85xx_PORPLLSR_QE_RATIO)