arm64: defconfig: Enable squashfs support

squashfs can be a convenient way to use a root filesystem stored as a
file on some other root filesystem.

Signed-off-by: Thierry Reding <treding@nvidia.com>
diff --git a/arch/arm64/configs/defconfig b/arch/arm64/configs/defconfig
index a112f21..71b1cfb 100644
--- a/arch/arm64/configs/defconfig
+++ b/arch/arm64/configs/defconfig
@@ -200,7 +200,7 @@
 CONFIG_TMPFS=y
 CONFIG_HUGETLBFS=y
 CONFIG_EFIVAR_FS=y
-# CONFIG_MISC_FILESYSTEMS is not set
+CONFIG_SQUASHFS=y
 CONFIG_NFS_FS=y
 CONFIG_NFS_V4=y
 CONFIG_ROOT_NFS=y