arm-toolchain: remove libmount-mountfd-support when using binary toolchain
util-linux is failing when compiling with:
| configure: error: libmount_mountfd_support selected, but required mount FDs based API not available
Remove this feature when building with the binary toolchain to avoid
this issue.
Acked-by: Denys Dmytriyenko <denys@konsulko.com>
Signed-off-by: Jon Mason <jon.mason@arm.com>
Jon Mason