target/arm: Declare support for FEAT_RASv1p1

target/arm: Declare support for FEAT_RASv1p1

The architectural feature RASv1p1 introduces the following new
features:
 * new registers ERXPFGCDN_EL1, ERXPFGCTL_EL1 and ERXPFGF_EL1
 * new bits in the fine-grained trap registers that control traps
   for these new registers
 * new trap bits HCR_EL2.FIEN and SCR_EL3.FIEN that control traps
   for ERXPFGCDN_EL1, ERXPFGCTL_EL1, ERXPFGP_EL1
 * a larger number of the ERXMISC<n>_EL1 registers
 * the format of ERR<n>STATUS registers changes

The architecture permits that if ERRIDR_EL1.NUM is 0 (as it is for
QEMU) then all these new registers may UNDEF, and the HCR_EL2.FIEN
and SCR_EL3.FIEN bits may be RES0.  We don't have any ERR<n>STATUS
registers (again, because ERRIDR_EL1.NUM is 0).  QEMU does not yet
implement the fine-grained-trap extension.  So there is nothing we
need to implement to be compliant with the feature spec.  Make the
'max' CPU report the feature in its ID registers, and document it.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220531114258.855804-1-peter.maydell@linaro.org