target/riscv: add DEFINE_PROP_END_OF_LIST() to riscv_cpu_options[]

target/riscv: add DEFINE_PROP_END_OF_LIST() to riscv_cpu_options[]

Add DEFINE_PROP_END_OF_LIST() and eliminate the ARRAY_SIZE() usage when
iterating in the riscv_cpu_options[] array, making it similar to what
we already do when working with riscv_cpu_extensions[].

We also have a more sophisticated motivation behind this change. In the
future we might need to export riscv_cpu_options[] to other files, and
ARRAY_LIST() doesn't work properly in that case because the array size
isn't exposed to the header file. Here's a future sight of what we would
deal with:

./target/riscv/kvm.c:1057:5: error: nested extern declaration of 'riscv_cpu_add_misa_properties' [-Werror=nested-externs]
n file included from ../target/riscv/kvm.c:19:
home/danielhb/work/qemu/include/qemu/osdep.h:473:31: error: invalid application of 'sizeof' to incomplete type 'const RISCVCPUMultiExtConfig[]'
 473 | #define ARRAY_SIZE(x) ((sizeof(x) / sizeof((x)[0])) + \
     |                               ^
./target/riscv/kvm.c:1047:29: note: in expansion of macro 'ARRAY_SIZE'
1047 |         for (int i = 0; i < ARRAY_SIZE(_array); i++) { \
     |                             ^~~~~~~~~~
./target/riscv/kvm.c:1059:5: note: in expansion of macro 'ADD_UNAVAIL_KVM_PROP_ARRAY'
1059 |     ADD_UNAVAIL_KVM_PROP_ARRAY(obj, riscv_cpu_extensions);
     |     ^~~~~~~~~~~~~~~~~~~~~~~~~~
home/danielhb/work/qemu/include/qemu/osdep.h:473:31: error: invalid application of 'sizeof' to incomplete type 'const RISCVCPUMultiExtConfig[]'
 473 | #define ARRAY_SIZE(x) ((sizeof(x) / sizeof((x)[0])) + \
     |                               ^
./target/riscv/kvm.c:1047:29: note: in expansion of macro 'ARRAY_SIZE'
1047 |         for (int i = 0; i < ARRAY_SIZE(_array); i++) { \

Homogenize the present and change the future by using
DEFINE_PROP_END_OF_LIST() in riscv_cpu_options[].

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-ID: <20230912132423.268494-5-dbarboza@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>