esmi: Clone open-source esmi repo as part of build

1. Remove esmi (internal gerrit) repo as git submodule
2. Clone esmi (open-source) repo during cmake using "git clone"
3. Download amd_hsmp.h header file during cmake build

TODO:
We can update the amd_hsmp.h to mainline linux kernel repo after
next Linux kernel release.

Change-Id: I763b5e287e24337c8e9e25f4e421cdb8698b9322

.gitmodules

@@ -1,4 +0,0 @@
-[submodule "e_smi_library"]
-	path = e_smi_library
-	url = ssh://gerritgit/SYS-MGMT/er/HPC/e_smi_library
-	branch = amd-dev