Enable LZ4 algorithm support

configname: CONFIG_ZRAM_LZ4_COMPRESS

Linux Kernel Configuration
└─>Device Drivers
└─>Block devices
└─>Enable LZ4 algorithm support
In linux kernel since version 3.15 (release Date: 2014-06-08)  
This option enables LZ4 compression algorithm support. Compression
algorithm can be changed using `comp_algorithm' device attribute.