[x86] Enable CONFIG_PWM_LPSS_PLATFORM as a module

Provides support for the low-level power subsystem handling
backlight control on GPD Pocket UMPC systems. Also enable its
dependency CONFIG_PWM=y (Closes: #895164).

debian/changelog

@@ -4,6 +4,10 @@ linux (4.16-1~exp1) UNRELEASED; urgency=medium
 
   [ Jeremy Stanley ]
   * [x86] Power management support for GPD Pocket UMPC systems
+    (Closes: #895164)
+    - Enable CONFIG_PWM_LPSS_PLATFORM as a module (provides support for the
+      low-level power subsystem handling backlight control) along with its
+      dependency CONFIG_PWM=y
     - Enable CONFIG_INTEL_INT0002_VGPIO as a module (provides support for the
       Bay Trail/Cherry Trail virtual GPIO controller to handle power events)
     - Enable CONFIG_REGULATOR (needed to build the already enabled

debian/config/kernelarch-x86/config

@@ -1424,6 +1424,12 @@ CONFIG_INTEL_RAPL=m
 ##
 CONFIG_PTP_1588_CLOCK_PCH=m
 
+##
+## file: drivers/pwm/Kconfig
+##
+CONFIG_PWM=y
+CONFIG_PWM_LPSS_PLATFORM=m
+
 ##
 ## file: drivers/regulator/Kconfig
 ##