README: switch to master branch for main development

Also updated to refer to DCAP driver for tracking proposed upstream version

Signed-off-by: Huang, Haitao <4699115+haitaohuang@users.noreply.github.com>

README.md

@@ -11,27 +11,22 @@ The Linux SGX software stack is comprised of the Intel(R) SGX driver, the Intel(
 
 The [linux-sgx-driver](https://github.com/01org/linux-sgx-driver) project hosts the out-of-tree driver for the Linux Intel(R) SGX software stack, which will be used until the driver upstreaming process is complete. 
 
-Within the linux-sgx-driver project, two versions of the out-of-tree driver are provided. Both versions are compatible with the linux-sgx PSW and SDK:
-- SGX 2.0 Linux Driver (sgx2 branch)
-  * The sgx2 branch of the linux-sgx-driver project contains the SGX 2.0 Linux Driver. This driver has additional support for SGX 2.0-based features available in upcoming CPUs. This driver has the same behavior as the SGX 1.5 Linux Driver (master) on CPUs without SGX 2.0 support.
-- SGX 1.5 Linux Driver (master branch)
-  * The master branch of the linux-sgx-driver project tracks the proposed upstream version of the SGX 1.5 driver and does not yet support SGX 2.0-based features.
-
 IMPORTANT:
 ---------
-Starting from 5/10/2019, the master branch (which supports only SGX 1.5-based features) is deprecated and is not supported anymore. Please use the sgx2 branch; it is a super set of the master branch.
+Starting 12/12/2019, the sgx2 branch is now merged into master. The sgx2 branch
+will be deprecated. All development and updates will be done on master branch going forward. Please use master branch only.
+
+The master branch will support both SGX 2.0 and SGX 1.5 features.
+
+Note this OOT driver may diverge from the proposed upstream version for in-kernel
+SGX support over time. The [DCAP
+driver](https://github.com/intel/SGXDataCenterAttestationPrimitives/tree/master/driver)
+will track more closely with proposed upstream in-kernel support.
 
 License
 -------
 See License.txt for details.
 
-Contributing
--------
-Starting from 05/2017, we are importing the sgx driver code from the in-kernel sgx repository located at git-hub: https://github.com/jsakkine-intel/linux-sgx.git. Any contribution should be done there. Future versions of the sgx driver code will be imported later on. The motivation behind this decision is to maintain a single source code of the sgx linux driver.
-An additional directory inker2ext/ has been created, it contains a script and a patch file that can be used in order to separately generate the code base of the sgx external module; it can be used in case someone wants the newest sgx driver as an external module and does not want to wait for next update.
-
-The sgx2 branch hosts an initial implementation supporting SGX 2.0. This patch is maintained in inker2ext/sgx2.patch in the 2.0 branch and will be periodically rebased to take updates from the linux-sgx-driver:master branch. Contributions for this patch should be managed directly through the linux-sgx-driver project on Github.
-
 Documentation
 -------------
 - [Intel(R) SGX for Linux\* OS](https://01.org/intel-softwareguard-extensions) project home page on [01.org](http://01.org)
@@ -87,7 +82,6 @@ Build and Install the Intel(R) SGX Driver
 
 
 ### Build the Intel(R) SGX Driver
-**Note:** To use the SGX 2.0 driver, checkout or download the sgx2 branch and then follow the build instructions.
 
 To build Intel(R) SGX driver, change the directory to the driver path and enter the following command:
 ```