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/device/Kconfig

@@ -51,7 +51,7 @@ config VGA_ROM_RUN
 	bool "Run VGA Option ROMs"
 	default n if PAYLOAD_SEABIOS
 	default y if !PAYLOAD_SEABIOS
-	depends on PCI && !MAINBOARD_DO_NATIVE_VGA_INIT && EXPERT
+	depends on PCI && !MAINBOARD_DO_NATIVE_VGA_INIT
 	help
 	  Execute VGA Option ROMs in coreboot if found. This is required
 	  to enable PCI/AGP/PCI-E video cards when not using a SeaBIOS
@@ -92,7 +92,7 @@ config ON_DEVICE_ROM_RUN
 	bool "Run Option ROMs on PCI devices"
 	default n if PAYLOAD_SEABIOS
 	default y if !PAYLOAD_SEABIOS
-	depends on PCI && EXPERT
+	depends on PCI
 	help
 	  Execute Option ROMs stored on PCI/PCIe/AGP devices in coreboot.
 
@@ -165,17 +165,12 @@ config YABEL_PCI_FAKE_WRITING_OTHER_DEVICES_CONFIG
 config YABEL_VIRTMEM_LOCATION
 	prompt "Location of YABEL's virtual memory"
 	hex
-	depends on PCI_OPTION_ROM_RUN_YABEL && EXPERT
+	depends on PCI_OPTION_ROM_RUN_YABEL
 	default 0x1000000
 	help
 	  YABEL requires 1MB memory for its CPU emulation. This memory is
 	  normally located at 16MB.
 
-config YABEL_VIRTMEM_LOCATION
-	hex
-	depends on PCI_OPTION_ROM_RUN_YABEL && !EXPERT
-	default 0x1000000
-
 config YABEL_DIRECTHW
 	prompt "Direct hardware access"
 	bool