powerpc: MPC8555: Remove macro CONFIG_MPC8555

Replace CONFIG_MPC8555 with ARCH_MPC8555 in Kconfig and clean up existing
macros.

Signed-off-by: York Sun <york.sun@nxp.com>
diff --git a/drivers/ddr/fsl/ctrl_regs.c b/drivers/ddr/fsl/ctrl_regs.c
index b2e92a0..32b0967 100644
--- a/drivers/ddr/fsl/ctrl_regs.c
+++ b/drivers/ddr/fsl/ctrl_regs.c
@@ -1831,7 +1831,7 @@
 	unsigned int clk_adjust;	/* Clock adjust */
 	unsigned int ss_en = 0;		/* Source synchronous enable */
 
-#if defined(CONFIG_ARCH_MPC8541) || defined(CONFIG_MPC8555)
+#if defined(CONFIG_ARCH_MPC8541) || defined(CONFIG_ARCH_MPC8555)
 	/* Per FSL Application Note: AN2805 */
 	ss_en = 1;
 #endif
diff --git a/drivers/ddr/fsl/mpc85xx_ddr_gen1.c b/drivers/ddr/fsl/mpc85xx_ddr_gen1.c
index 67a9ad8..c005f52 100644
--- a/drivers/ddr/fsl/mpc85xx_ddr_gen1.c
+++ b/drivers/ddr/fsl/mpc85xx_ddr_gen1.c
@@ -47,7 +47,7 @@
 	out_be32(&ddr->timing_cfg_2, regs->timing_cfg_2);
 	out_be32(&ddr->sdram_mode, regs->ddr_sdram_mode);
 	out_be32(&ddr->sdram_interval, regs->ddr_sdram_interval);
-#if defined(CONFIG_MPC8555) || defined(CONFIG_ARCH_MPC8541)
+#if defined(CONFIG_ARCH_MPC8555) || defined(CONFIG_ARCH_MPC8541)
 	out_be32(&ddr->sdram_clk_cntl, regs->ddr_sdram_clk_cntl);
 #endif
 
diff --git a/drivers/input/keyboard.c b/drivers/input/keyboard.c
index f53a07a..7af5868 100644
--- a/drivers/input/keyboard.c
+++ b/drivers/input/keyboard.c
@@ -21,7 +21,7 @@
 static int kbd_read_keys(struct input_config *config)
 {
 #if defined(CONFIG_MPC5xxx) || defined(CONFIG_ARCH_MPC8540) || \
-		defined(CONFIG_ARCH_MPC8541) || defined(CONFIG_MPC8555)
+		defined(CONFIG_ARCH_MPC8541) || defined(CONFIG_ARCH_MPC8555)
 	/* no ISR is used, so received chars must be polled */
 	ps2ser_check();
 #endif