drivers: adc: Kconfig: Remove redundant 'default n' properties

Bool symbols implicitly default to 'n'.

A 'default n' can make sense e.g. in a Kconfig.defconfig file, if you
want to override a 'default y' on the base definition of the symbol. It
isn't used like that on any of these symbols though, and is
inconsistent.

This will make the auto-generated Kconfig documentation have "No
defaults. Implicitly defaults to n." as well, which is clearer than
'default n if ...'

Signed-off-by: Ulf Magnusson <Ulf.Magnusson@nordicsemi.no>

drivers/adc/Kconfig.dw

@@ -10,7 +10,6 @@ menuconfig ADC_DW
 	bool "ARC Designware Driver"
 	depends on ARC
 	select ADC_0
-	default n
 	help
 	  Enable the driver implementation of the Designware ADC IP.
 

drivers/adc/Kconfig.mcux

@@ -10,6 +10,5 @@ config ADC_MCUX_ADC16
 	bool "MCUX ADC16 driver"
 	depends on HAS_MCUX_ADC16
 	select HAS_DTS_ADC
-	default n
 	help
 	  Enable the MCUX ADC16 driver.

drivers/adc/Kconfig.qmsi

@@ -10,7 +10,6 @@ menuconfig ADC_QMSI
 	bool "QMSI ADC Driver"
 	depends on QMSI
 	select ADC_0
-	default n
 	help
 	  Enable the driver implementation of the QMSI ADC IP.
 
@@ -18,7 +17,6 @@ menuconfig ADC_QMSI_SS
 	bool "QMSI ADC Driver for the Sensor Subsystem"
 	depends on QMSI
 	select ADC_0
-	default n
 	help
 	  Enable the driver implementation of the QMSI ADC IP.
 

drivers/adc/Kconfig.sam_afec

@@ -10,7 +10,6 @@ menuconfig ADC_SAM_AFEC
 	bool "SAM ADC Driver"
 	depends on SOC_FAMILY_SAM
 	select HAS_DTS_ADC
-	default n
 	help
 	  Enable Atmel SAM MCU Family Analog-to-Digital Converter (ADC) driver
 	  based on AFEC module.

drivers/adc/Kconfig.ti_adc108s102

@@ -10,7 +10,6 @@ menuconfig ADC_TI_ADC108S102
 	bool "TI adc108s102 chip driver"
 	select SPI
 	select ADC_0
-	default n
 	help
 	  Enable support for TI's ADC chip adc108s102 driver.