x86: conga-qeval20-qa3: Add missing MAINTERNERS entry

Add entry for the missing internal UART defconfig to the MAINTAINERS
file.

Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Bin Meng <bmeng.cn@gmail.com>
CC: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>

board/congatec/conga-qeval20-qa3-e3845/MAINTAINERS

@@ -4,4 +4,5 @@ S:	Maintained
 F:	board/congatec/conga-qeval20-qa3-e3845
 F:	include/configs/conga-qeval20-qa3-e3845.h
 F:	configs/conga-qeval20-qa3-e3845_defconfig
+F:	configs/conga-qeval20-qa3-e3845-internal-uart_defconfig
 F:	arch/x86/dts/conga-qeval20-qa3-e3845.dts