soc/amd/stoneyridge: remove unused config_t typedef

Change-Id: I1456fe069c4b0cf859f769e0144ec62cff0f3987
Signed-off-by: Felix Held <felix-coreboot@felixheld.de>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/48319
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Marshall Dawson <marshalldawson3rd@gmail.com>

src/soc/amd/stoneyridge/chip.h

@@ -66,6 +66,4 @@ struct soc_amd_stoneyridge_config {
 	u8 lvds_poseq_blon_to_varybl;
 };
 
-typedef struct soc_amd_stoneyridge_config config_t;
-
 #endif /* __STONEYRIDGE_CHIP_H__ */