ARM: AM3517-EVM: Update Maintainer

The previous e-mail pointing to Vaibhav Hiremath <hvaibhav@ti.com>
is bouncing and has for some time.  This updates it to myself and I
work for Logic PD the manufacturer of the AM3517-SOM and EVM
Signed-off-by: NAdam Ford <aford173@gmail.com>

board/logicpd/am3517evm/MAINTAINERS

 AM3517EVM BOARD
-M:	Vaibhav Hiremath <hvaibhav@ti.com>
+M:	Adam Ford <aford173@gmail.com>
 S:	Maintained
 F:	board/logicpd/am3517evm/
 F:	include/configs/am3517_evm.h