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

CONFIG_MXS_HAVE_PLATFORM_MXS_PWM (not configurable)

modulename: platform-mxs-pwm.ko

configname: CONFIG_MXS_HAVE_PLATFORM_MXS_PWM

Linux Kernel Configuration
└─>MXS_HAVE_PLATFORM_MXS_PWM
In linux kernel since version 2.6.39 (release Date: 2011-05-18)  
source code:
is depended by
CONFIG_MODULE_TX28