[new uImage] Update naming convention for bootm/uImage related code

This patch introduces the following prefix convention for the
image format handling and bootm related code:

genimg_		- dual format shared code
image_		- legacy uImage format specific code
fit_		- new uImage format specific code
boot_		- booting process related code

Related routines are renamed and a few pieces of code are moved around and
re-grouped.

Signed-off-by: Marian Balakowicz <m8@semihalf.com>

lib_arm/bootm.c

@@ -95,7 +95,7 @@ void do_bootm_linux (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[],
 		printf ("Using machid 0x%x from environment\n", machid);
 	}
 
-	get_ramdisk (cmdtp, flag, argc, argv, images,
+	boot_get_ramdisk (cmdtp, flag, argc, argv, images,
 			IH_ARCH_ARM, &initrd_start, &initrd_end);
 
 	show_boot_progress (15);