risu_reginfo_aarch64: fix output formatting issue

print regs in hex and missing spaces.

Signed-off-by: Claudio Fontana <claudio.fontana@linaro.org>
aarch64.risu: add LDNP / STNP 32bit/64bit

NB: this triggers a bug (in Foundation Models?), or I dont understand,
regardless of the data sync barriers put before and after each
LDNP/STNP. Also adds testcase prova-ldst_np.bin with the offending
example.

Signed-off-by: Claudio Fontana <claudio.fontana@huawei.com>