boot: change some arch ifdefs to feature ifdefs

The routines boot_ramdisk_high, boot_get_cmdline and boot_get_kbd
are currently enabled by various combinations of CONFIG_M68K,
CONFIG_POWERPC and CONFIG_SPARC.

Use CONFIG_SYS_BOOT_<FEATURE> defines instead.

CONFIG_SYS_BOOT_RAMDISK_HIGH
CONFIG_SYS_BOOT_GET_CMDLINE
CONFIG_SYS_BOOT_GET_KBD

Define these as appropriate in arch/include/asm/config.h files.

Signed-off-by: John Rigby <john.rigby@linaro.org>
Acked-by: Wolfgang Denk <wd@denx.de>
diff --git a/common/cmd_bootm.c b/common/cmd_bootm.c
index 25bc39c..ce3c77c 100644
--- a/common/cmd_bootm.c
+++ b/common/cmd_bootm.c
@@ -472,7 +472,7 @@
 static cmd_tbl_t cmd_bootm_sub[] = {
 	U_BOOT_CMD_MKENT(start, 0, 1, (void *)BOOTM_STATE_START, "", ""),
 	U_BOOT_CMD_MKENT(loados, 0, 1, (void *)BOOTM_STATE_LOADOS, "", ""),
-#if defined(CONFIG_PPC) || defined(CONFIG_M68K) || defined(CONFIG_SPARC)
+#ifdef CONFIG_SYS_BOOT_RAMDISK_HIGH
 	U_BOOT_CMD_MKENT(ramdisk, 0, 1, (void *)BOOTM_STATE_RAMDISK, "", ""),
 #endif
 #ifdef CONFIG_OF_LIBFDT
@@ -528,7 +528,7 @@
 			lmb_reserve(&images.lmb, images.os.load,
 					(load_end - images.os.load));
 			break;
-#if defined(CONFIG_PPC) || defined(CONFIG_M68K) || defined(CONFIG_SPARC)
+#ifdef CONFIG_SYS_BOOT_RAMDISK_HIGH
 		case BOOTM_STATE_RAMDISK:
 		{
 			ulong rd_len = images.rd_end - images.rd_start;