target/riscv: Rename tcg_cpu_FOO() to include 'riscv'

target/riscv: Rename tcg_cpu_FOO() to include 'riscv'

The tcg_cpu_FOO() names are riscv specific, so rename
them as riscv_tcg_cpu_FOO() (as other names in this file)
to ease navigating the code.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-ID: <20240111120221.35072-6-philmd@linaro.org>