xlat v2: Clean debug xlat tables descriptor print

The previous debug output for EL1&0 translation regimes was too verbose,
which makes it hard to read and hides the intent behind the parameters
assigned to each region. This patch simplifies this output and makes the
outputs for EL3 and EL1&0 mostly the same. The difference is that in
EL1&0 it is specified whether the region is exclusively accessible from
EL1 (PRIV) or both EL0 and EL1 (USER).

For example:

    MEM-RW(PRIV)-NOACCESS(USER)-XN(PRIV)-XN(USER)-S
    MEM-RO(PRIV)-NOACCESS(USER)-EXEC(PRIV)-EXEC(USER)-S

After the change, it becomes this:

    MEM-RW-XN-PRIV-S
    MEM-RO-EXEC-PRIV-S

Change-Id: I15f4b99058429d42107fbf89e15f4838a9b559a5
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>