This patch adds additional data rates to the GNAT.Serial_Communications
package (Linux version).

Tested on x86_64-pc-linux-gnu, committed on trunk

2019-07-08  Bob Duff  <duff@adacore.com>

gcc/ada/

	* libgnat/g-sercom.ads, libgnat/g-sercom__linux.adb (Data_Rate):
	Support additional data rates.