syscalls: greatly simplify system call declaration

To define a system call, it's now sufficient to simply tag the inline
prototype with "__syscall" or "__syscall_inline" and include a special
generated header at the end of the header file.

The system call dispatch table and enumeration of system call IDs is now
automatically generated.

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
diff --git a/doc/zephyr.doxyfile b/doc/zephyr.doxyfile
index 16a4721..a135882 100644
--- a/doc/zephyr.doxyfile
+++ b/doc/zephyr.doxyfile
@@ -281,7 +281,9 @@
 			 "CONFIG_BT_BREDR=y" \
 			 "__deprecated=" \
 			 "__printf_like(x, y)=" \
-			 "__attribute(x)__="
+			 "__attribute(x)__=" \
+			 "__syscall=" \
+			 "__syscall_inline="
 EXPAND_AS_DEFINED      =
 SKIP_FUNCTION_MACROS   = NO
 #---------------------------------------------------------------------------