board/synopsys: remove patch for linux vdk defconfig

board/synopsys: remove patch for linux vdk defconfig

The patch for linux vdk defconfig introduced ARC_SMP_HALT_ON_RESET
config symbol. In fact that is not required as this symbol is enabled by
default if ARC_UBOOT_SUPPORT config symbol is set (and it is set in
vdk configs).

Also this commit fixes build failure, pointed us by Arnout:
https://gitlab.com/buildroot.org/buildroot/builds/14419270

Signed-off-by: Vlad Zakharov <vzakhar@synopsys.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>