cpu: Expose CPU microcode information

This commit exposes the CPU microcode information.

Signed-off-by: Simarpreet Singh <simar@opendns.com>

README.rst

@@ -133,6 +133,7 @@ Several methods have been added which are not present in psutil, but will provid
   - Mhz
   - CacheSize
   - Flags        (ex: "fpu vme de pse tsc msr pae mce cx8 ...")
+  - Microcode
 
 - load/LoadAvg()  (linux, freebsd)
 
@@ -262,6 +263,7 @@ hostname              x     x      x       x       x
   CoreID              x
   Cores               x                            x
   ModelName           x     x      x       x       x
+  Microcode           x
 **LoadAvg**
   Load1               x     x      x       x
   Load5               x     x      x       x

cpu/cpu.go

@@ -40,6 +40,7 @@ type InfoStat struct {
 	Mhz        float64  `json:"mhz"`
 	CacheSize  int32    `json:"cacheSize"`
 	Flags      []string `json:"flags"`
+	Microcode  string   `json:"microcode"`
 }
 
 type lastPercent struct {

cpu/cpu_linux.go

@@ -186,6 +186,8 @@ func Info() ([]InfoStat, error) {
 			c.Flags = strings.FieldsFunc(value, func(r rune) bool {
 				return r == ',' || r == ' '
 			})
+		case "microcode":
+			c.Microcode = value
 		}
 	}
 	if c.CPU >= 0 {