defconfig: switch to zstd as default zswap compression algorithm

* since we've backported zstd, let's use it as our default zswap compression algorithm

Signed-off-by: Cyber Knight <cyberknight755@gmail.com>

Author: cyberknight777

arch/arm64/configs/neternels_defconfig

@@ -647,6 +647,9 @@ CONFIG_FRONTSWAP=y
 CONFIG_CMA=y
 CONFIG_CMA_AREAS=7
 CONFIG_ZSWAP=y
+# CONFIG_ZSWAP_DEF_COMP_LZ4 is not set
+CONFIG_ZSWAP_DEF_COMP_ZSTD=y
+CONFIG_ZSWAP_DEF_COMP="zstd"
 CONFIG_ZPOOL=y
 # CONFIG_ZBUD is not set
 # CONFIG_Z3FOLD is not set