correct flash size about ch55xduino

[DeqingSun]

You are right, On chapter 2 of datasheet, 16K can be configured to all app space or 14K app + 2K bootloader. I supposed all ch55xduino uses a 2K bootloader.
On Chapter 6.2,

Code Flash includes the application code of the low address area and the boot code of the high address area, 
and it is also possible to combine two block areas to save a single application code.

For CH551, Code Flash's application code area is only 10KB.

Seems CH551 doesn't count 2K bootloader into the 10K specs.

[DeqingSun]

cf9a28f
should fix this.