libutils malloc: fix alignment for arm64
libutils malloc: fix alignment for arm64

Alignment of returned buffer was prior to this patch set to 8 for all
platforms.  This isn't enough for arm64 where some buffers need to be 16
byte aligned instead.

This patch sets required alignment for returned buffers to 8 for ILP32
platforms and 16 for LP64 platforms.

Reviewed-by: Jerome Forissier <ced78d268b4c9a0a20a59a9feeebd2ad90da03d3@linaro.org>
Reviewed-by: Pascal Brand <0b55292d2562685bad4ce52d64f802e8f1cd299e@linaro.org>
Signed-off-by: Jens Wiklander <7706914404370d7502c27a0eff493dcf491feb51@linaro.org>

pascal-brand-st-dev/optee_os,matt2048/optee_os,pascal-brand-st-dev/optee_os,matt2048/optee_os,matt2048/optee_os,pascal-brand-st-dev/optee_os,pascal-brand-st-dev/optee_os,matt2048/optee_os,cedric-chaumont-st-dev/optee_os,cedric-chaumont-st-dev/optee_os,cedric-chaumont-st-dev/optee_os,pascal-brand-st-dev/optee_os,cedric-chaumont-st-dev/optee_os