configs: atmel: add support for sama5d2 xplained boot from sd card

This defconfig allows to build all the components to boot from a sd card on a
SAMA5D2 Xplained board. For more details, please read the
board/atmel/readme.txt file.

Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

configs/atmel_sama5d2_xplained_mmc_defconfig

@@ -0,0 +1,26 @@
+BR2_arm=y
+BR2_cortex_a5=y
+BR2_ARM_ENABLE_NEON=y
+BR2_ARM_ENABLE_VFP=y
+BR2_ARM_FPU_VFPV4=y
+BR2_ARM_INSTRUCTIONS_THUMB2=y
+BR2_PACKAGE_HOST_LINUX_HEADERS_CUSTOM_4_1=y
+BR2_LINUX_KERNEL=y
+BR2_LINUX_KERNEL_CUSTOM_GIT=y
+BR2_LINUX_KERNEL_CUSTOM_REPO_URL="https://github.com/linux4sam/linux-at91.git"
+BR2_LINUX_KERNEL_CUSTOM_REPO_VERSION="linux4sam_5.2"
+BR2_LINUX_KERNEL_DEFCONFIG="sama5"
+BR2_LINUX_KERNEL_ZIMAGE=y
+BR2_LINUX_KERNEL_DTS_SUPPORT=y
+BR2_LINUX_KERNEL_INTREE_DTS_NAME="at91-sama5d2_xplained at91-sama5d2_xplained_pda4 at91-sama5d2_xplained_pda7 at91-sama5d2_xplained_pda7b"
+BR2_TARGET_AT91BOOTSTRAP3=y
+BR2_TARGET_AT91BOOTSTRAP3_CUSTOM_GIT=y
+BR2_TARGET_AT91BOOTSTRAP3_CUSTOM_REPO_URL="https://github.com/linux4sam/at91bootstrap.git"
+BR2_TARGET_AT91BOOTSTRAP3_CUSTOM_REPO_VERSION="v3.8.4"
+BR2_TARGET_AT91BOOTSTRAP3_DEFCONFIG="sama5d2_xplainedsd_uboot"
+BR2_TARGET_UBOOT=y
+BR2_TARGET_UBOOT_BUILD_SYSTEM_KCONFIG=y
+BR2_TARGET_UBOOT_CUSTOM_GIT=y
+BR2_TARGET_UBOOT_CUSTOM_REPO_URL="https://github.com/linux4sam/u-boot-at91.git"
+BR2_TARGET_UBOOT_CUSTOM_REPO_VERSION="linux4sam_5.2"
+BR2_TARGET_UBOOT_BOARD_DEFCONFIG="sama5d2_xplained_mmc"