Fix MIMC200 board LCD init

This patch updates the LCD init code for the MIMC200 board.

V2 fixes a .yres typo and corrects an incorrect setup value
in the call to at32_add_device_lcdc()

Without this patch, the lcd setup is wrong and won't display images
correctly (if at all !!)

Signed-off-by: Mark Jackson <mpfj@mimc.co.uk>
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>