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

CONFIG_SAMSUNG_DEV_PWM (not configurable)

modulename: dev-pwm.ko

configname: CONFIG_SAMSUNG_DEV_PWM

Linux Kernel Configuration
└─>SAMSUNG_DEV_PWM
In linux kernel since version 2.6.39 (release Date: 2011-05-18)  
Compile in platform device definition for PWM Timer

source code:
arch/arm/plat-samsung/dev-pwm.c
depends
CONFIG_PLAT_SAMSUNG |
| CONFIG_SAMSUNG_ATAGS