hw/intc/arm_gicv3_kvm: silence the compiler warnings

hw/intc/arm_gicv3_kvm: silence the compiler warnings

When using -Wimplicit-fallthrough in our CFLAGS, the compiler showed warning:
hw/intc/arm_gicv3_kvm.c: In function ‘kvm_arm_gicv3_put’:
hw/intc/arm_gicv3_kvm.c:484:13: warning: this statement may fall through [-Wimplicit-fallthrough=]
             kvm_gicc_access(s, ICC_AP0R_EL1(1), ncpu, &reg64, true);
             ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
hw/intc/arm_gicv3_kvm.c:485:9: note: here
         default:
         ^~~~~~~
hw/intc/arm_gicv3_kvm.c:495:13: warning: this statement may fall through [-Wimplicit-fallthrough=]
             kvm_gicc_access(s, ICC_AP1R_EL1(2), ncpu, &reg64, true);
             ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
hw/intc/arm_gicv3_kvm.c:496:9: note: here
         case 6:
         ^~~~
hw/intc/arm_gicv3_kvm.c:498:13: warning: this statement may fall through [-Wimplicit-fallthrough=]
             kvm_gicc_access(s, ICC_AP1R_EL1(1), ncpu, &reg64, true);
             ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
hw/intc/arm_gicv3_kvm.c:499:9: note: here
         default:
         ^~~~~~~

hw/intc/arm_gicv3_kvm.c: In function ‘kvm_arm_gicv3_get’:
hw/intc/arm_gicv3_kvm.c:634:37: warning: this statement may fall through [-Wimplicit-fallthrough=]
             c->icc_apr[GICV3_G0][2] = reg64;
             ~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~
hw/intc/arm_gicv3_kvm.c:635:9: note: here
         case 6:
         ^~~~
hw/intc/arm_gicv3_kvm.c:637:37: warning: this statement may fall through [-Wimplicit-fallthrough=]
             c->icc_apr[GICV3_G0][1] = reg64;
             ~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~
hw/intc/arm_gicv3_kvm.c:638:9: note: here
         default:
         ^~~~~~~
hw/intc/arm_gicv3_kvm.c:648:39: warning: this statement may fall through [-Wimplicit-fallthrough=]
             c->icc_apr[GICV3_G1NS][2] = reg64;
             ~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~
hw/intc/arm_gicv3_kvm.c:649:9: note: here
         case 6:
         ^~~~
hw/intc/arm_gicv3_kvm.c:651:39: warning: this statement may fall through [-Wimplicit-fallthrough=]
             c->icc_apr[GICV3_G1NS][1] = reg64;
             ~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~
hw/intc/arm_gicv3_kvm.c:652:9: note: here
         default:
         ^~~~~~~

Reported-by: Euler Robot <euler.robot@huawei.com>
Signed-off-by: Chen Qun <kuhn.chenqun@huawei.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20201211152426.350966-7-thuth@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>