[MXNET-674] Speed up GPU builds in CI (#12782)
[MXNET-674] Speed up GPU builds in CI (#12782)

* [MXNET-674] Speed up GPU builds in CI

* [MXNET-674] Refactor SMs into shell variable

* [MXNET-674] Build CMake GPU CI jobs without PTX

ptrendx/mxnet,leezu/mxnet,yajiedesign/mxnet,eric-haibin-lin/mxnet,sxjscience/mxnet,zhreshold/mxnet,tlby/mxnet,eric-haibin-lin/mxnet,ForkedReposBak/mxnet,DickJC123/mxnet,reminisce/mxnet,ptrendx/mxnet,DickJC123/mxnet,zhreshold/mxnet,leezu/mxnet,sxjscience/mxnet,yajiedesign/mxnet,leezu/mxnet,zhreshold/mxnet,ptrendx/mxnet,reminisce/mxnet,zhreshold/mxnet,ForkedReposBak/mxnet,apache/incubator-mxnet,yajiedesign/mxnet,szha/mxnet,eric-haibin-lin/mxnet,sxjscience/mxnet,leezu/mxnet,ptrendx/mxnet,larroy/mxnet,zhreshold/mxnet,reminisce/mxnet,eric-haibin-lin/mxnet,dmlc/mxnet,zhreshold/mxnet,sxjscience/mxnet,tlby/mxnet,dmlc/mxnet,tlby/mxnet,dmlc/mxnet,dmlc/mxnet,leezu/mxnet,szha/mxnet,leezu/mxnet,reminisce/mxnet,reminisce/mxnet,reminisce/mxnet,ForkedReposBak/mxnet,ptrendx/mxnet,larroy/mxnet,szha/mxnet,dmlc/mxnet,sxjscience/mxnet,DickJC123/mxnet,tlby/mxnet,ForkedReposBak/mxnet,tlby/mxnet,apache/incubator-mxnet,ptrendx/mxnet,sxjscience/mxnet,reminisce/mxnet,larroy/mxnet,zhreshold/mxnet,dmlc/mxnet,zhreshold/mxnet,larroy/mxnet,yajiedesign/mxnet,yajiedesign/mxnet,reminisce/mxnet,ForkedReposBak/mxnet,DickJC123/mxnet,eric-haibin-lin/mxnet,ptrendx/mxnet,sxjscience/mxnet,leezu/mxnet,leezu/mxnet,ptrendx/mxnet,larroy/mxnet,szha/mxnet,tlby/mxnet,ForkedReposBak/mxnet,tlby/mxnet,zhreshold/mxnet,ForkedReposBak/mxnet,tlby/mxnet,tlby/mxnet,sxjscience/mxnet,ptrendx/mxnet,larroy/mxnet,reminisce/mxnet,yajiedesign/mxnet,szha/mxnet,dmlc/mxnet,yajiedesign/mxnet,dmlc/mxnet,larroy/mxnet,larroy/mxnet,yajiedesign/mxnet,larroy/mxnet,szha/mxnet,eric-haibin-lin/mxnet,apache/incubator-mxnet,ptrendx/mxnet,leezu/mxnet,reminisce/mxnet,eric-haibin-lin/mxnet,ForkedReposBak/mxnet,szha/mxnet,yajiedesign/mxnet,szha/mxnet,dmlc/mxnet,ForkedReposBak/mxnet,eric-haibin-lin/mxnet,szha/mxnet,apache/incubator-mxnet,eric-haibin-lin/mxnet,tlby/mxnet,sxjscience/mxnet