contrib/gitdm: Add Rivos Inc to the domain map

Whatever they are up to a number of people for the company are
contributing to QEMU so lets group them together.

Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com>
Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20231106185112.2755262-18-alex.bennee@linaro.org>

contrib/gitdm/domain-map

@@ -38,6 +38,7 @@ proxmox.com     Proxmox
 quicinc.com     Qualcomm Innovation Center
 redhat.com      Red Hat
 rev.ng          rev.ng Labs
+rivosinc.com    Rivos Inc
 rt-rk.com       RT-RK
 samsung.com     Samsung
 siemens.com     Siemens