x86: conga: theadorable-x86-conga-qa3-e3845_defconfig: Misc defconfig updates

- Disable debug UART
- Enable more partition support

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