ARM: configs: at91: DT/ATAG defconfig modifications

As all AT91 platforms are converted to DT for a long time, adapt the
defconfigs by:
- removing legacy CONFIG_ATAGS as a DT will always be provided;
- removing the CONFIG_ARM_APPENDED_DTB option on SAMA5 devices as the
  vast majority of systems will use a DT-aware bootloader on these
  devices.
Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>

arch/arm/configs/at91_dt_defconfig

@@ -17,6 +17,7 @@ CONFIG_SOC_SAM9X60=y
 # CONFIG_ATMEL_CLOCKSOURCE_PIT is not set
 CONFIG_AEABI=y
 CONFIG_UACCESS_WITH_MEMCPY=y
+# CONFIG_ATAGS is not set
 CONFIG_ARM_APPENDED_DTB=y
 CONFIG_ARM_ATAG_DTB_COMPAT=y
 CONFIG_CMDLINE="console=ttyS0,115200 initrd=0x21100000,25165824 root=/dev/ram0 rw"

arch/arm/configs/sama5_defconfig

@@ -19,7 +19,7 @@ CONFIG_SOC_SAMA5D3=y
 CONFIG_SOC_SAMA5D4=y
 # CONFIG_ATMEL_CLOCKSOURCE_PIT is not set
 CONFIG_UACCESS_WITH_MEMCPY=y
-CONFIG_ARM_APPENDED_DTB=y
+# CONFIG_ATAGS is not set
 CONFIG_CMDLINE="console=ttyS0,115200 initrd=0x21100000,25165824 root=/dev/ram0 rw"
 CONFIG_KEXEC=y
 CONFIG_VFP=y