libkmsxx: Add include of <cerrno.h> to various files

Test: Boot to UI with BeagleBoard X15
Change-Id: I323cbcc908056765ea231991d70488452c0010a5
Signed-off-by: Andrew F. Davis <afd@ti.com>
diff --git a/kms++/src/card.cpp b/kms++/src/card.cpp
index f7f1a5a..d71db7c 100644
--- a/kms++/src/card.cpp
+++ b/kms++/src/card.cpp
@@ -5,6 +5,7 @@
 #include <stdexcept>
 #include <string.h>
 #include <algorithm>
+#include <cerrno>
 
 #include <xf86drm.h>
 #include <xf86drmMode.h>
diff --git a/kms++/src/dumbframebuffer.cpp b/kms++/src/dumbframebuffer.cpp
index b21e8ff..4419687 100644
--- a/kms++/src/dumbframebuffer.cpp
+++ b/kms++/src/dumbframebuffer.cpp
@@ -1,5 +1,6 @@
 
 #include <cstring>
+#include <cerrno>
 #include <stdexcept>
 #include <sys/mman.h>
 #include <xf86drm.h>
diff --git a/kms++/src/extframebuffer.cpp b/kms++/src/extframebuffer.cpp
index c1f562e..12e59b7 100644
--- a/kms++/src/extframebuffer.cpp
+++ b/kms++/src/extframebuffer.cpp
@@ -1,5 +1,7 @@
 
 #include <cstring>
+#include <cerrno>
+
 #include <stdexcept>
 #include <sys/mman.h>
 #include <xf86drm.h>