Kconfig: Remove EXPERT mode

After much consideration, and many years of an EXPERT mode sitting
almost completely unused, we've seen that it doesn't work for us.
There is no standard on what constitutes EXPERT, and most of
coreboot's options Kconfig are expert-level.

We even joked that not selecting "EXPERT" should prevent coreboot
from compiling:

@echo $(shell whoami) is not permitted to compile coreboot

Change-Id: Ic22dd54a48190b81d711625efb6b9f3078f41778
Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
Reviewed-on: http://review.coreboot.org/11365
Tested-by: build bot (Jenkins)
Reviewed-by: Alexander Couzens <lynxis@fe80.eu>

src/Kconfig

@@ -22,14 +22,6 @@ mainmenu "coreboot configuration"
 
 menu "General setup"
 
-config EXPERT
-	bool "Expert mode"
-	help
-	  This allows you to select certain advanced configuration options.
-
-	  Warning: Only enable this option if you really know what you are
-	  doing! You have been warned!
-
 config LOCALVERSION
 	string "Local version string"
 	help
@@ -111,7 +103,6 @@ config CCACHE
 config FMD_GENPARSER
 	bool "Generate flashmap descriptor parser using flex and bison"
 	default n
-	depends on EXPERT
 	help
 	  Enable this option if you are working on the flashmap descriptor
 	  parser and made changes to fmd_scanner.l or fmd_parser.y.
@@ -121,7 +112,6 @@ config FMD_GENPARSER
 config SCONFIG_GENPARSER
 	bool "Generate SCONFIG parser using flex and bison"
 	default n
-	depends on EXPERT
 	help
 	  Enable this option if you are working on the sconfig device tree
 	  parser and made changes to sconfig.l or sconfig.y.
@@ -283,7 +273,6 @@ config BOOTBLOCK_SOURCE
 config SKIP_MAX_REBOOT_CNT_CLEAR
 	bool "Do not clear reboot count after successful boot"
 	default n
-	depends on EXPERT
 	help
 	  Do not clear the reboot count immediately after successful boot.
 	  Set to allow the payload to control normal/fallback image recovery.