MAINTAINERS: Take maintainership of TI KeyStone2 support

Add arch/arm/mach-keystone/ into K2 board directory MAINTAINERS file.

Convert current entries into regex match style.

Assign maintainership to myself.

Signed-off-by: Andrew Davis <afd@ti.com>
diff --git a/board/ti/ks2_evm/MAINTAINERS b/board/ti/ks2_evm/MAINTAINERS
index 999ef0a..637feec 100644
--- a/board/ti/ks2_evm/MAINTAINERS
+++ b/board/ti/ks2_evm/MAINTAINERS
@@ -1,12 +1,9 @@
-KS2_EVM BOARD
-M:	Vitaly Andrianov <vitalya@ti.com>
+KeyStone II EVM Boards
+M:	Andrew Davis <afd@ti.com>
 S:	Maintained
+F:	arch/arm/mach-keystone/
 F:	board/ti/ks2_evm/
-F:	include/configs/k2hk_evm.h
-F:	configs/k2hk_evm_defconfig
-F:	include/configs/k2e_evm.h
-F:	configs/k2e_evm_defconfig
-F:	include/configs/k2l_evm.h
-F:	configs/k2l_evm_defconfig
-F:	include/configs/k2g_evm.h
-F:	configs/k2g_evm_defconfig
+N:	k2hk
+N:	k2e
+N:	k2l
+N:	k2g