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/configs/stemmy_defconfig b/configs/stemmy_defconfig
index 77bc5c7..cf86146 100644
--- a/configs/stemmy_defconfig
+++ b/configs/stemmy_defconfig
@@ -1,6 +1,9 @@
 CONFIG_ARM=y
 CONFIG_SKIP_LOWLEVEL_INIT=y
 CONFIG_ARCH_U8500=y
+CONFIG_SUPPORT_PASSING_ATAGS=y
+# CONFIG_SETUP_MEMORY_TAGS is not set
+CONFIG_INITRD_TAG=y
 CONFIG_SYS_TEXT_BASE=0x100000
 CONFIG_NR_DRAM_BANKS=2
 CONFIG_SYS_MALLOC_LEN=0x0200000