configs/freescale_imx6ullevk: kernel build needs host-openssl

With the kernel to 4.19, the kernel configuration needs host-openssl
to build.

Fixes:
scripts/extract-cert.c:21:10: fatal error: openssl/bio.h: No such file or directory
   21 | #include <openssl/bio.h>

Signed-off-by: Julien Olivain <julien.olivain@oss.nxp.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

configs/freescale_imx6ullevk_defconfig

@@ -10,6 +10,7 @@ BR2_LINUX_KERNEL_CUSTOM_REPO_VERSION="rel_imx_4.19.35_1.1.0"
 BR2_LINUX_KERNEL_DEFCONFIG="imx_v7"
 BR2_LINUX_KERNEL_DTS_SUPPORT=y
 BR2_LINUX_KERNEL_INTREE_DTS_NAME="imx6ull-14x14-evk"
+BR2_LINUX_KERNEL_NEEDS_HOST_OPENSSL=y
 BR2_TARGET_ROOTFS_EXT2=y
 BR2_TARGET_ROOTFS_EXT2_4=y
 BR2_TARGET_UBOOT=y