target/arm: Add MO_128 entry to pred_esz_masks[]

In commit 7390e0e9, we added support for SME loads and stores.
Unlike SVE loads and stores, these include handling of 128-bit
elements.  The SME load/store functions call down into the existing
sve_cont_ldst_elements() function, which uses the element size MO_*
value as an index into the pred_esz_masks[] array.  Because this code
path now has to handle MO_128, we need to add an extra element to the
array.

This bug was spotted by Coverity because it meant we were reading off
the end of the array.

Resolves: Coverity CID 1490539, 1490541, 1490543, 1490544, 1490545,
 1490546, 1490548, 1490549, 1490550, 1490551, 1490555, 1490557,
 1490558, 1490560, 1490561, 1490563
Fixes: 7390e0e9 ("target/arm: Implement SME LD1, ST1")
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220718100144.3248052-1-peter.maydell@linaro.org