[tables] Redefine methods for accessing linker tables

Intel's C compiler (icc) chokes on the zero-length arrays that we
currently use as part of the mechanism for accessing linker table
entries.  Abstract away the zero-length arrays, to make a port to icc
easier.

Introduce macros such as for_each_table_entry() to simplify the common
case of iterating over all entries in a linker table.

Represent table names as #defined string constants rather than
unquoted literals; this avoids visual confusion between table names
and C variable or type names, and also allows us to force a
compilation error in the event of incorrect table names.

src/include/console.h

@@ -85,6 +85,9 @@ struct console_driver {
 	int ( *iskey ) ( void );
 };
 
+/** Console driver table */
+#define CONSOLES "consoles"
+
 /**
  * Mark a <tt> struct console_driver </tt> as being part of the
  * console drivers table.
@@ -102,7 +105,7 @@ struct console_driver {
  * @endcode
  *
  */
-#define __console_driver __table ( struct console_driver, console, 01 )
+#define __console_driver __table ( struct console_driver, CONSOLES, 01 )
 
 /* Function prototypes */