configs/imx6qsabreauto: Use zImage by default

Currently the generated sdcard.img does not boot because U-Boot looks for
a zImage type of kernel instead of uImage.

Remove the generation of uImage, so that the sdcard.img can successfully
boot.

Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

configs/freescale_imx6qsabreauto_defconfig

@@ -17,8 +17,6 @@ BR2_LINUX_KERNEL_CUSTOM_GIT=y
 BR2_LINUX_KERNEL_CUSTOM_REPO_URL="git://git.freescale.com/imx/linux-2.6-imx.git"
 BR2_LINUX_KERNEL_CUSTOM_REPO_VERSION="rel_imx_4.1.15_1.1.0_ga"
 BR2_LINUX_KERNEL_DEFCONFIG="imx_v7"
-BR2_LINUX_KERNEL_UIMAGE=y
-BR2_LINUX_KERNEL_UIMAGE_LOADADDR="0x10008000"
 BR2_LINUX_KERNEL_DTS_SUPPORT=y
 BR2_LINUX_KERNEL_INTREE_DTS_NAME="imx6q-sabreauto"