ARM: 8979/1: Remove redundant ARCH_SPARSEMEM_DEFAULT setting

If ARCH_SPARSEMEM_ENABLE=y and ARCH_{FLATMEM,DISCONTIGMEM}_ENABLE=n,
then the logic in mm/Kconfig already makes CONFIG_SPARSEMEM the only
choice.  This is true for all of the existing ARM users of
ARCH_SPARSEMEM_ENABLE.

Forcing ARCH_SPARSEMEM_DEFAULT=y if ARCH_SPARSEMEM_ENABLE=y prevents
us from ever defaulting to FLATMEM, so we should remove this setting.

Link: https://lkml.org/lkml/2015/6/4/757



Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
Tested-by: Stephen Boyd <sboyd@codeaurora.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Gregory Fong <gregory.0xf0@gmail.com>
Signed-off-by: Doug Berger <opendmb@gmail.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Mike Rapoport <mike.rapoport@gmail.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>