hw/intc/arm_gicv3_cpuif(): Remove redundant tests of is_a64()

hw/intc/arm_gicv3_cpuif(): Remove redundant tests of is_a64()

In the gicv3_{irq,fiq,irqfiq}_access() functions, in the
arm_current_el(env) == 3 case we do the following test:
    if (!is_a64(env) && !arm_is_el3_or_mon(env)) {
        r = CP_ACCESS_TRAP_EL3;
    }

In this check, the "!is_a64(env)" is redundant, because if
we are at EL3 and in AArch64 then arm_is_el3_or_mon() will
return true and we will skip the if() body anyway.

Remove the unnecessary tests.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20250130182309.717346-9-peter.maydell@linaro.org