[LPC1114] fixed to erase sector 0 to END_SECTOR

On LPC11xx_32 and LPC8xx_4 target, EraseChip only erased sector 0. Now,
EraseChip erase sector 0 to END_SECTOR.
Merge pull request #58 from ytsuboi/master

[LPC1114] fixed to erase sector 0 to END_SECTOR