powerpc/mpc8xxx: Move HWCONFIG_BUFFER_SIZE into config.h

Before proper environment is setup, we extract hwconfig and put it into a
buffer with size HWCONFIG_BUFFER_SIZE. We need to enlarge the buffer to
accommodate longer string. Since this macro is used in multiple files, we
move it into arch/powerpc/include/asm/config.h.

Signed-off-by: York Sun <yorksun@freescale.com>
Signed-off-by: Andy Fleming <afleming@freescale.com>
diff --git a/arch/powerpc/cpu/mpc85xx/cpu_init.c b/arch/powerpc/cpu/mpc85xx/cpu_init.c
index f293265..afb5671 100644
--- a/arch/powerpc/cpu/mpc85xx/cpu_init.c
+++ b/arch/powerpc/cpu/mpc85xx/cpu_init.c
@@ -48,8 +48,6 @@
 
 #include "../../../../drivers/block/fsl_sata.h"
 
-#define HWCONFIG_BUFFER_SIZE 128
-
 DECLARE_GLOBAL_DATA_PTR;
 
 #ifdef CONFIG_QE
diff --git a/arch/powerpc/cpu/mpc85xx/fsl_corenet_serdes.c b/arch/powerpc/cpu/mpc85xx/fsl_corenet_serdes.c
index 8aac1de..2a68060 100644
--- a/arch/powerpc/cpu/mpc85xx/fsl_corenet_serdes.c
+++ b/arch/powerpc/cpu/mpc85xx/fsl_corenet_serdes.c
@@ -46,8 +46,6 @@
 
 static u32 serdes_prtcl_map;
 
-#define HWCONFIG_BUFFER_SIZE	128
-
 #ifdef DEBUG
 static const char *serdes_prtcl_str[] = {
 	[NONE] = "NA",
diff --git a/arch/powerpc/cpu/mpc8xxx/ddr/options.c b/arch/powerpc/cpu/mpc8xxx/ddr/options.c
index 2923456..13e4825 100644
--- a/arch/powerpc/cpu/mpc8xxx/ddr/options.c
+++ b/arch/powerpc/cpu/mpc8xxx/ddr/options.c
@@ -19,7 +19,6 @@
  * This is pretty fragile on both the use of stack and if the buffer is big
  * enough. However we will get a warning from getenv_f for the later.
  */
-#define HWCONFIG_BUFFER_SIZE	128
 
 /* Board-specific functions defined in each board's ddr.c */
 extern void fsl_ddr_board_options(memctl_options_t *popts,
diff --git a/arch/powerpc/include/asm/config.h b/arch/powerpc/include/asm/config.h
index d138636..67cea01 100644
--- a/arch/powerpc/include/asm/config.h
+++ b/arch/powerpc/include/asm/config.h
@@ -29,6 +29,10 @@
 #include <asm/config_mpc86xx.h>
 #endif
 
+#ifndef HWCONFIG_BUFFER_SIZE
+  #define HWCONFIG_BUFFER_SIZE 256
+#endif
+
 /* CONFIG_HARD_SPI triggers SPI bus initialization in PowerPC */
 #if defined(CONFIG_MPC8XXX_SPI) || defined(CONFIG_FSL_ESPI)
 # ifndef CONFIG_HARD_SPI