arch/arm/src/lpc54xx: Clone the LPC1788 LCD driver. The LPC54628 LCD...

arch/arm/src/lpc54xx:  Clone the LPC1788 LCD driver.  The LPC54628 LCD interface is identical.  The initial commit is a brute force clone.  It still needs review to make sure the LDC is appropriately enabled in the SYSCON and that clocking is provided.  Also, extend the SPI 'skeleton' file so that has a place to support for SPI DMA and the SPI exchange method.