Kconfig: regularize selection of CONFIG_BINFMT_ELF

with mips converted to use of fs/config_binfmt_elf.c, there's no
need to keep selects of that thing all over arch/* - we can simply
turn into def_bool y if COMPAT && BINFMT_ELF (in fs/Kconfig.binfmt)
and get rid of all selects.

Several architectures got those selects wrong (e.g. you could
end up with sparc64 sans BINFMT_ELF, with select violating
dependencies, etc.)

Randy Dunlap has spotted some of those; IMO this is simpler than
his fix, but it depends upon the stuff that would need to be
backported, so we might end up using his variant for -stable.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

arch/sparc/Kconfig

@@ -494,7 +494,6 @@ config COMPAT
 	bool
 	depends on SPARC64
 	default y
-	select COMPAT_BINFMT_ELF
 	select HAVE_UID16
 	select ARCH_WANT_OLD_COMPAT_IPC
 	select COMPAT_OLD_SIGACTION