config: Update envs for trats and trats2 - Disable L2 cache

Disable L2 caches for Trats and Trats2 devices.

It turns out that for data downloading with thordown command L2 cache
disablement brings a significant speed improvement.

rootfs - 400 MiB:
- L2 cache enabled:			2.69 MiB/s
- L2 cache disabled: 			5.56 MiB/s

Such improvement is possible due to reduction of the need to invalidate
redundant data, which resides in L2 cache.

Since the sent USB request size at once is 512B (L1 - 32 KiB in total) -
one can be quite confident that it is already available in L1 and L2 can
be disabled.

Signed-off-by: Lukasz Majewski <l.majewski@samsung.com>
Acked-by: Minkyu Kang <mk7.kang@samsung.com>