cpu/intel/stm: Use URLs so a link is generated

Change-Id: I21b1f681a3e6def66149b74c62eb9b0c52bd7249
Signed-off-by: Paul Menzel <[email protected]>

Author: paulmenzel

cpu/intel/stm/README.md

@@ -39,7 +39,7 @@ interface with the STM:
 
 SMI Transfer Monitor (STM) User Guide, August 2015
 
-The above document can be obtained from firmware.intel.com.
+The above document can be obtained from https://firmware.intel.com.
 
 The STM-PE interface is defined in the Readme.STMPE file found on
-the stmpe branch of review.coreboot.org/STM.
+the stmpe branch of https://review.coreboot.org/STM.