Kconfig: Move CONFIG_BOOTSTAGE to Kconfig

Move CONFIG_BOOT_STAGE and its associated options to Kconfig. Adjust
existing users and code.

Signed-off-by: Simon Glass <sjg@chromium.org>

README

@@ -3198,55 +3198,6 @@ CBFS (Coreboot Filesystem) support
 		example, some LED's) on your board. At the moment,
 		the following checkpoints are implemented:
 
-- Detailed boot stage timing
-		CONFIG_BOOTSTAGE
-		Define this option to get detailed timing of each stage
-		of the boot process.
-
-		CONFIG_BOOTSTAGE_USER_COUNT
-		This is the number of available user bootstage records.
-		Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
-		a new ID will be allocated from this stash. If you exceed
-		the limit, recording will stop.
-
-		CONFIG_BOOTSTAGE_REPORT
-		Define this to print a report before boot, similar to this:
-
-		Timer summary in microseconds:
-		       Mark    Elapsed  Stage
-			  0          0  reset
-		  3,575,678  3,575,678  board_init_f start
-		  3,575,695         17  arch_cpu_init A9
-		  3,575,777         82  arch_cpu_init done
-		  3,659,598     83,821  board_init_r start
-		  3,910,375    250,777  main_loop
-		 29,916,167 26,005,792  bootm_start
-		 30,361,327    445,160  start_kernel
-
-		CONFIG_CMD_BOOTSTAGE
-		Add a 'bootstage' command which supports printing a report
-		and un/stashing of bootstage data.
-
-		CONFIG_BOOTSTAGE_FDT
-		Stash the bootstage information in the FDT. A root 'bootstage'
-		node is created with each bootstage id as a child. Each child
-		has a 'name' property and either 'mark' containing the
-		mark time in microsecond, or 'accum' containing the
-		accumulated time for that bootstage id in microseconds.
-		For example:
-
-		bootstage {
-			154 {
-				name = "board_init_f";
-				mark = <3575678>;
-			};
-			170 {
-				name = "lcd";
-				accum = <33482>;
-			};
-		};
-
-		Code in the Linux kernel can find this in /proc/devicetree.
 
 Legacy uImage format: