USB MSD using the AHBSRAM banks 0 and 1 to create a 32k RAM disk. After FAT format 12kb is writable

Dependencies:   USBDevice USBMSD_RAM mbed

Fork of USB-MSD_SD_HelloWorld_Mbed-RAMVersion by avnish aggarwal

Revision:
27:92a4e3cf24db
Parent:
25:989ca460ad95