mb/emulation/qemu-i440fx: Remove TRACE=y from test build

Looks like the option is generally not compatible with
garbage collections. Nothing is inlined, is_smp_boot()
no longer evaluates to constant false and thus the symbols
from secondary.S would need to be present for the build
to pass after we set SMP=n.

Change-Id: I1b76dc34b5f39d8988368f71a0a2f43d1bc4177e
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/43817
Reviewed-by: Nico Huber <nico.h@gmx.de>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

configs/config.emulation_qemu_x86_i440fx_debug

@@ -4,6 +4,5 @@ CONFIG_FATAL_ASSERTS=y
 CONFIG_DEBUG_CBFS=y
 CONFIG_DEBUG_PIRQ=y
 CONFIG_DEBUG_MALLOC=y
-CONFIG_TRACE=y
 CONFIG_DEBUG_BOOT_STATE=y
 CONFIG_DEBUG_ADA_CODE=y