uboot-imx

x86: Include bss subsections in linker script

When we build with -fdata-sections we may end up with bss subsections. Our
linker script explicitly lists only a single consecutive bss section though.

Adapt the statement to also include subsections.

This fixes booting efi-x86_app_defconfig.

Signed-off-by: Alexander Graf <agraf@suse.de>