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>
diff --git a/board/friendlyarm/nanopi2/hwrev.h b/board/friendlyarm/nanopi2/hwrev.h
index 1b1a828..4033031 100644
--- a/board/friendlyarm/nanopi2/hwrev.h
+++ b/board/friendlyarm/nanopi2/hwrev.h
@@ -9,7 +9,7 @@
 
 extern void bd_hwrev_init(void);
 extern void bd_base_rev_init(void);
-extern u32 get_board_rev(void);
+extern u32 get_board_revision(void);
 extern const char *get_board_name(void);
 
 #endif /* __BD_HW_REV_H__ */