mx5: Add workaround for ARM erratum ID 468414

mx5: Add workaround for ARM erratum ID 468414

Add the software workaround for ARM erratum ID 468414.

According to mx53/mx51 errata document:

"ENGcm11133 - ARM: NEON load data can be incorrectly forwarded to a
subsequent request

Description:

Under very specific set of conditions, data from a Neon load request can be incorrectly forwarded
to a subsequent, unrelated memory request.
The conditions are as follows:
• Neon loads and stores must be in use
• Neon L1 caching must be disabled
• Trustzone must be configured and in use
• The secure memory address space and the non-secure memory address space both use the same
physical addresses, either as an alias or the same memory location or for separate memory
locations
The issue is reported by ARM, erratum ID 468414, Category 2"

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>