mtd: cfi: enforce valid geometry configuration

MTD allows compile-time configuration of the possible CFI geometry
settings that are allowed by the kernel, but that includes a couple of
invalid configurations, where no bank width or no interleave setting
is allowed. These are then caught with a compile-time warning:

include/linux/mtd/cfi.h:76:2: warning: #warning No CONFIG_MTD_CFI_Ix selected. No NOR chip support can work.
include/linux/mtd/map.h:145:2: warning: #warning "No CONFIG_MTD_MAP_BANK_WIDTH_xx selected. No NOR chip support can work"

This is a bit annoying for randconfig tests, and can be avoided if
we change the Kconfig logic to always select the simplest configuration
when no other one is enabled.

Signed-off-by: Arnd Bergmann <[e-mail]>
Signed-off-by: Brian Norris <[e-mail]>

drivers/mtd/chips/Kconfig

···
 config MTD_CFI_GEOMETRY
 	bool "Specific CFI Flash geometry selection"
 	depends on MTD_CFI_ADV_OPTIONS
+	select MTD_MAP_BANK_WIDTH_1 if  !(MTD_MAP_BANK_WIDTH_2 || \
+		 MTD_MAP_BANK_WIDTH_4  || MTD_MAP_BANK_WIDTH_8 || \
+		 MTD_MAP_BANK_WIDTH_16 || MTD_MAP_BANK_WIDTH_32)
+	select MTD_CFI_I1 if !(MTD_CFI_I2 || MTD_CFI_I4 || MTD_CFI_I8)
 	help
 	  This option does not affect the code directly, but will enable
 	  some other configuration options which would allow you to reduce