CONFIG_S3C64XX_PL080 is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

CONFIG_S3C64XX_PL080 (not configurable)

configname: CONFIG_S3C64XX_PL080

Linux Kernel Configuration
└─>Samsung S3C64XX
└─>S3C64XX_PL080
In linux kernel since version 3.10 (release Date: 2013-06-30)