message: Amend memory layout to match tock 1.5 release
diff: MEMORY {
  /* The application region is 64 bytes (0x40) */
  FLASH (rx) : ORIGIN = 0x00030040, LENGTH = 0x0005FFC0
  - SRAM (rwx) : ORIGIN = 0x20002000, LENGTH = 62K
  + SRAM (rwx) : ORIGIN = 0x20004000, LENGTH = 62K
  }
  /*
  