added reference for hp workstation

README.md

@@ -86,7 +86,7 @@ If you need a SGX capable server have a look at the [Intel SGX server block](htt
 | Laptop | HP  | Pavilion 15-ab251ur  | [see Issue 14](https://github.com/ayeks/SGX-hardware/issues/14) | 18 February 2017 | HP Pavilion 15-ab251ur, CPU i7-6500U |
 | Laptop | ASUS | X456UA | [see Issue 18](https://github.com/ayeks/SGX-hardware/issues/18) | 18 April 2017 |  |
 | Workstation | HP  | Z2 Mini G3  | [see Pull request 19](https://github.com/ayeks/SGX-hardware/pull/19) | 21 April 2017 | HP Z2 Mini G3, CPU Xeon E3-1245 v5 |
-| Workstation | HP  | HP Z240 Tower Workstation  | N51 Ver. 01.54 ] | 16 Mar 2017 | HP Z240 Tower Workstation, Intel(R) Xeon(R) CPU E3-1240 v5 @ 3.50GHz|
+| Workstation | HP  | HP Z240 Tower Workstation  | [see Pull request 23](https://github.com/ayeks/SGX-hardware/pull/23) | 16 Mar 2017 | HP Z240 Tower Workstation, Intel(R) Xeon(R) CPU E3-1240 v5 @ 3.50GHz|
 | Server | Supermicro | system [5019-MR](http://www.supermicro.com/products/system/1U/5019/SYS-5019S-MR.cfm), mainboard [X11SSH-F BIOS 1.0b or 2.0b](http://www.supermicro.com/products/motherboard/Xeon/C236_C232/X11SSH-F.cfm) | [Pressrelease](http://www.supermicro.com/newsroom/pressreleases/2015/press150901_Embedded_IoT_Skylake.cfm) [see Issue 6](https://github.com/ayeks/SGX-hardware/issues/6) | 19 May 2016| [platform services only on specific ME versions](https://github.com/ayeks/SGX-hardware/issues/24) |
 
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