Added locking mechanism to periperials on SPI1.
Added DMA mode read/write routine to SPI Flash. (Debug reuiqred. WARNING: !!! ENABLING DMA MODE MAY DESTROY YOUR DATA IN THE SPI FLASH !!!)
git-svn-id: https://rt-thread.googlecode.com/svn/trunk@538 bbd45198-f89e-11dd-88c7-29a3b14d5316