target/riscv: redirect XVentanaCondOps to use the Zicond functions

target/riscv: redirect XVentanaCondOps to use the Zicond functions

The Zicond standard extension implements the same instruction
semantics as XVentanaCondOps, although using different mnemonics and
opcodes.

Point XVentanaCondOps to the (newly implemented) Zicond implementation
to reduce the future maintenance burden.

Also updating MAINTAINERS as trans_xventanacondops.c.inc.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Philipp Tomsich <philipp.tomsich@vrull.eu>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20230307180708.302867-3-philipp.tomsich@vrull.eu>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>