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>
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 6cff14a..b44f709 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -465,4 +465,13 @@
 	  assigned to PCI devices - i.e. the memory and prefetch regions, as
 	  passed to pci_set_region().
 
+config BOOTSTAGE
+	default y
+
+config BOOTSTAGE_REPORT
+	default y
+
+config CMD_BOOTSTAGE
+	default y
+
 endmenu