CONFIG_CASIO_E55 is not available for thedefaultarchitecture x86.
Result is shown for architecture mips

Support for CASIO CASSIOPEIA E-10/15/55/65

configname: CONFIG_CASIO_E55

Linux Kernel Configuration
└─>Support for CASIO CASSIOPEIA E-10/15/55/65
In linux kernel since version 2.6.12