CONFIG_ARCH_U300 is not available for thedefaultarchitecture x86.
Result is shown for architecture arm
ST-Ericsson U300 Series
modulename: u300.ko
configname: CONFIG_ARCH_U300
ARM system type
└─>ST-Ericsson U300 Series
In linux kernel since version 2.6.31 (release Date: 2009-09-09)
Support for ST-Ericsson U300 series mobile platforms.