Since KERNEL_SWAP is only enabled by default for !SMALL_FLASH targets, we need
to check if the current kernel supports swap before trying to configure
zram-swap, as opkg can't check for kernel dependencies.
Signed-off-by: Rui Salvaterra <rsalvaterra@gmail.com>
(cherry picked from commit 565dfeb1280343fb3f838581169e5d7a1c947862)