drm/ttm: Try to check if new ttm man out of bounds during compile

Allow TTM know if vendor set new ttm mananger out of bounds by adding
build_bug_on.

Signed-off-by: xinhui pan <xinhui.pan@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210913080950.180752-1-xinhui.pan@amd.com


Signed-off-by: Christian König <christian.koenig@amd.com>