drm/radeon/kms: fix i2c map for rv250/280

Those chips have crt2_ddc bus.

Fixes:
https://bugzilla.kernel.org/show_bug.cgi?id=39672

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/radeon/radeon_combios.c

@@ -779,7 +779,8 @@ void radeon_combios_i2c_init(struct radeon_device *rdev)
 				}
 			}
 		}
-	} else if (rdev->family >= CHIP_R200) {
+	} else if ((rdev->family == CHIP_R200) ||
+		   (rdev->family >= CHIP_R300)) {
 		/* 0x68 */
 		i2c = combios_setup_i2c_bus(rdev, DDC_MONID, 0, 0);
 		rdev->i2c_bus[3] = radeon_i2c_create(dev, &i2c, "MONID");