remove enable_cache() of 3 mainboards

Because enable cache is added at the end of disable_cache_as_ram,
( http://review.coreboot.org/#/c/1662/2/src/cpu/amd/agesa/cache_as_ram.inc )
enable_cache() should be removed. The 3 mainboards are: amd parmer,
amd thatcher and tyan s8226

Change-Id: If870ca07d2e97b9e860a2e2315f551251c7a4ed2
Signed-off-by: Siyuan Wang <SiYuan.Wang@amd.com>
Signed-off-by: Siyuan Wang <wangsiyuanbuaa@gmail.com>
Reviewed-on: http://review.coreboot.org/1669
Reviewed-by: Marc Jones <marcj303@gmail.com>
Tested-by: build bot (Jenkins)
3 files changed