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

PXA based Palm PDAs

configname: CONFIG_ARCH_PXA_PALM

Linux Kernel Configuration
└─>Intel PXA2xx/PXA3xx Implementations
└─>PXA based Palm PDAs
In linux kernel since version 2.6.27 (release Date: 2008-10-09)  
selects
CONFIG_HAVE_PWM

depends
CONFIG_ARCH_PXA

is selected by
CONFIG_MACH_CENTRO