board/zynqmp/kria/kv260/uboot.fragment: remove unnecessary CONFIG_MULTI_DTB_FIT option

This patch removes the CONFIG_MULTI_DTB_FIT u-boot option for the
zynqmp_kria_kv260_defconfig as it is not necessary.  The post build
kv260.sh creates the proper u-boot.itb without needing this option.

Fixes:

  https://gitlab.com/buildroot.org/buildroot/-/jobs/3310463281

Signed-off-by: Neal Frager <neal.frager@amd.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

board/zynqmp/kria/kv260/uboot.fragment

@@ -1,7 +1,6 @@
 CONFIG_DEFAULT_DEVICE_TREE="zynqmp-smk-k26-revA"
 CONFIG_SYS_SPI_U_BOOT_OFFS=0xF80000
 CONFIG_DTB_RESELECT=y
-CONFIG_MULTI_DTB_FIT=y
 CONFIG_DMA=y
 CONFIG_XILINX_DPDMA=y
 CONFIG_PHY=y