When the debug option is enabled ECC DSA test doesn't have enough stack
space so qemu fails. Adding double stack size for special case of qemu
and CONFIG_DEBUG.
Jira: ZEP-1066
Change-Id: Ib14d853de2b1c755a6171787845433648d61b75b
Signed-off-by: Genaro Saucedo Tejada <genaro.saucedo.tejada@intel.com>