ARM: omap2plus_defconfig: Fix bloat caused by having ipv6 built-in

Commit  673ce00c (ARM: omap2plus_defconfig: Add support for
distros with systemd) caused considerable bloat as noted by
Paul Walmsley <paul@pwsan.com>.

Let's fix this issue by making what we can into loadable modules
for the systemd options. That's only IPV6 and AUTOFS4_FS it
seems, and IPv6 defaults to a loadable module.
Reported-by: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/configs/omap2plus_defconfig

@@ -86,7 +86,6 @@ CONFIG_IP_PNP_DHCP=y
 CONFIG_IP_PNP_BOOTP=y
 CONFIG_IP_PNP_RARP=y
 # CONFIG_INET_LRO is not set
-CONFIG_IPV6=y
 CONFIG_NETFILTER=y
 CONFIG_CAN=m
 CONFIG_CAN_C_CAN=m
@@ -317,7 +316,7 @@ CONFIG_EXT4_FS=y
 CONFIG_FANOTIFY=y
 CONFIG_QUOTA=y
 CONFIG_QFMT_V2=y
-CONFIG_AUTOFS4_FS=y
+CONFIG_AUTOFS4_FS=m
 CONFIG_MSDOS_FS=y
 CONFIG_VFAT_FS=y
 CONFIG_TMPFS=y