common/board_r: Fix booting issue on T4240QDS

common/board_r: Fix booting issue on T4240QDS

Commit 294b91a5817147d4b7f47be2ac69bac2a1f26491 moved initr_malloc
earlier than initr_unlock_ram_in_cache. This causes issue on T4240.
It may be related to locked L1 d-cache and unlocked L2 cache. D-
cache could and should be unlock earlier for normal operation.

This patch moves initr_unlock_ram_in_cache before initr_malloc. It
has been verified on the following boards, in which only T4240QDS
suffered and has been since fixed: T4240QDS, T2080QDS, P5040DS,
P4080DS, MPC8572DS, MPC8536DS, MPC8641HPCN, B4860QDS.

Signed-off-by: York Sun <yorksun@freescale.com>
CC: Scott Wood <scottwood@freescale.com>
CC: Simon Glass <sjg@chromium.org>
Acked-by: Simon Glass <sjg@chromium.org>