display-hal: Exclude HWC libs compilation.

This change introduces compilation flag to
compile standalone SDM libs.

Change-Id: I3f8cde50e1806c6cf157364657d77fd9a780d5e3
diff --git a/sdm/include/utils/sys.h b/sdm/include/utils/sys.h
index c06b7f8..b90007a 100644
--- a/sdm/include/utils/sys.h
+++ b/sdm/include/utils/sys.h
@@ -49,7 +49,11 @@
 #endif
 
   // Pointers to system calls which are either mapped to actual system call or virtual driver.
+#ifdef TARGET_HEADLESS
+  typedef int (*ioctl)(int, unsigned long int, ...);  // NOLINT
+#else
   typedef int (*ioctl)(int, int, ...);
+#endif
   typedef int (*open)(const char *, int, ...);
   typedef int (*close)(int);
   typedef int (*poll)(struct pollfd *, nfds_t, int);