Convert CMake files to 4 spaces indentation

src/unix/CMakeLists.txt

@@ -1,3 +1,20 @@
+#
+# 86Box     A hypervisor and IBM PC system emulator that specializes in
+#           running old operating systems and software designed for IBM
+#           PC systems and compatibles from 1981 through fairly recent
+#           system designs based on the PCI bus.
+#
+#           This file is part of the 86Box distribution.
+#
+#           CMake build script.
+#
+# Authors:  Cacodemon345
+#           David Hrdlička, <hrdlickadavid@outlook.com>
+#
+#           Copyright 2021 Cacodemon345.
+#           Copyright 2021 David Hrdlička.
+#
+
 add_library(plat OBJECT unix.c)
 
 if (NOT CPPTHREADS)