Added all symbols to assembler (not just FPU_PRESENT=1). Removed unused c ...

compiler argument.

Misc fixes for LPC4088/LPC4088DM: ...

- Resetting in LPCXpresso IDE did not reset the LCD controller which
  sometimes could cause strange behaviour
- The ROM_LAT bit in the MATRIXARB register must be set in order to
  prevent a HardFault when debugging
- The change of compiler in LPCXpresso IDE to ARM launchpad GCC5 was
  causing build errors due to multiply defined timeval symbol.
- The exporters for LPCXpresso IDE did not set the FPU_PRESENT define
  for assembler, only for c/c++. This caused very strange behaviour
  in the RTOS code (e.g. timeouts no longer working, context switches
  failing etc.)

Fixed target issues for TARGET_LPC4088_DM ...

- Removed target alias from the EXPORT_MAP in targets.py as it didn't work
- Added copies of the LPC4088 target exporters
- Fixed flag issue in the gcc toolchain
- Changed defines in eth USBDevice, rpt and rtos to handle
  TARGET_LPC4088_DM