Kconfig: Change the minimum SMP_NCPUS to 1

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

drivers/lcd/st7565.c: Use ST7565_POWERCTRL_INT instead of ST7565_POWERCTRL_BRF

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

The attached .patch implements DMA support for the stm32f4 I2C. Max and I have verified that it works on our systems.

WIP: Add support for Mikroelektronika Clicker 2 for STM32

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

sem_holder:Clean up from Review

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

Spelling and backward DEBUGASSERT along with one gem

  if (sem->holder[0].htcb != NULL || sem->holder[**1**].htcb != NULL)

implement storage for commonly accessed parameters
implement parameter retrieval

XMC4xxx:  Clean up problems associated with USIC initialization.  USIC still does not work in UART mode.