Previously, in AArch32, `IMAGE_XLAT_DEFAULT_REGIME` wasn't defined. The
translation regime is only used in the AArch64 port of the translation
tables library v2, so this is not a problem for now, but future patches
will use it.

`IMAGE_EL` isn't used in AArch32, so it isn't needed to define it.

Change-Id: I4acdb01a58658956ab94bd82ed5b7fee1aa6ba90
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>