target/arm: Fix {fp, sve}_exception_el for VHE mode running

When HCR_EL2.E2H is set, the format of CPTR_EL2 changes to
look more like CPACR_EL1, with ZEN and FPEN fields instead
of TZ and TFP fields.

Reported-by: Zenghui Yu <yuzenghui@huawei.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20220127063428.30212-4-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>