distro: use imply to enable DISTRO_DEFAULTS as SoC default

The default of DISTRO_DEFAULTS is messy.  Using the 'imply' keyword
is equivalent and cleaner.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

Kconfig

@@ -68,11 +68,6 @@ config CC_COVERAGE
 
 config DISTRO_DEFAULTS
 	bool "Select defaults suitable for booting general purpose Linux distributions"
-	default y if ARCH_SUNXI || TEGRA
-	default y if ARCH_LS2080A
-	default y if ARCH_MESON
-	default y if ARCH_ROCKCHIP
-	default n
 	imply USE_BOOTCOMMAND
 	select CMD_BOOTZ if ARM && !ARM64
 	select CMD_BOOTI if ARM64

arch/arm/Kconfig

@@ -584,6 +584,7 @@ config ARCH_OMAP2PLUS
 
 config ARCH_MESON
 	bool "Amlogic Meson"
+	imply DISTRO_DEFAULTS
 	help
 	  Support for the Meson SoC family developed by Amlogic Inc.,
 	  targeted at media players and tablet computers. We currently
@@ -723,6 +724,7 @@ config ARCH_SUNXI
 	select USB_KEYBOARD if DISTRO_DEFAULTS
 	select USE_TINY_PRINTF
 	imply CMD_GPT
+	imply DISTRO_DEFAULTS
 	imply FAT_WRITE
 	imply OF_LIBFDT_OVERLAY
 	imply PRE_CONSOLE_BUFFER
@@ -784,6 +786,7 @@ config ARCH_ZYNQMP
 
 config TEGRA
 	bool "NVIDIA Tegra"
+	imply DISTRO_DEFAULTS
 	imply FAT_WRITE
 
 config TARGET_VEXPRESS64_AEMV8A
@@ -1183,6 +1186,7 @@ config ARCH_ROCKCHIP
 	select ENABLE_ARM_SOC_BOOT0_HOOK
 	select SPI
 	imply CMD_FASTBOOT
+	imply DISTRO_DEFAULTS
 	imply FASTBOOT
 	imply FAT_WRITE
 	imply USB_FUNCTION_FASTBOOT

arch/arm/cpu/armv8/fsl-layerscape/Kconfig

@@ -167,6 +167,7 @@ config ARCH_LS2080A
 	select SYS_I2C_MXC_I2C2
 	select SYS_I2C_MXC_I2C3
 	select SYS_I2C_MXC_I2C4
+	imply DISTRO_DEFAULTS
 	imply PANIC_HANG
 
 config FSL_LSCH2

doc/README.distro

@@ -165,8 +165,7 @@ Enabling the distro options
 In your board's defconfig, enable the DISTRO_DEFAULTS option by adding
 a line with "CONFIG_DISTRO_DEFAULTS=y". If you want to enable this
 from Kconfig itself, for e.g. all boards using a specific SoC then
-add a "default y if ARCH_FOO" to the DISTRO_DEFAULTS section of
-the Kconfig file in the root of the u-boot sources.
+add a "imply DISTRO_DEFAULTS" to your SoC CONFIG option.
 
 In your board configuration file, include the following: