arm: Disable ATAGs support

With the exceptions of ds109, ds414, icnova-a20-swac, nokia_rx51 and
stemmy, disable ATAG support.  A large number of platforms had enabled
support but never supported a kernel so old as to require it.  Further,
some platforms are old enough to support both, but are well supported by
devicetree booting, and have been for a number of years.  This is
because some of the ATAGs related functions have been re-used to provide
the same kind of information, but for devicetree or just generally to
inform the user.  When needed still, rename these functions to
get_board_revision() instead, to avoid conflicts.  In other cases, these
functions were simply unused, so drop them.

Cc: Andre Przywara <andre.przywara@arm.com>
Cc: Jagan Teki <jagan@amarulasolutions.com>
Cc: Phil Sutter <phil@nwl.cc>
Cc: Stefan Bosch <stefan_b@posteo.net>
Signed-off-by: Tom Rini <trini@konsulko.com>

include/configs/display5.h

@@ -47,11 +47,6 @@
 
 #include "imx6_spl.h"
 
-#define CONFIG_CMDLINE_TAG
-#define CONFIG_SETUP_MEMORY_TAGS
-#define CONFIG_INITRD_TAG
-#define CONFIG_REVISION_TAG
-
 #define CONFIG_MXC_UART_BASE		UART5_BASE
 
 /* I2C Configs */