Merged in raiden00/nuttx (pull request #469)

Master

* stm32f0/Kconfig: remove references to HRTIM

* STM32F33: missing SYSCFG CFGR3 definitions

* stm32_hrtim.h: remove redundant definitions

* stm32_hrtim.c: fix DAC triggers configuration

* stm32_hritm.c: warning message when default value selected

* stm32_hrtim.c: missing master timer logic

* stm32_hrtim.c: add more assertions

* stm32_dac.c: fix conditional

* stm32_dac.c: conditional logic for timer triggering

* stm32_dac.c: fix TSEL configuration when HRTIM

* stm32_dac.c: unnecessary condition

* stm32_dac.c: DMA request remapping

* stm32_dac.c: fix commpilation errors

* stm32_dac.c: add DMA buffers initialization logic

* stm32_hrtim.c: enable DAC triggering

* analog/comp.c: fix compilation errors when poll disabled

* stm32_hrtim.c: remove doubled assertions

Approved-by: Gregory Nutt <gnutt@nuttx.org>