Add EHCI and OHCI USB host drivers for the Ingenic JZ4780 SoC, derived
from the existing sama5 implementation.
Additionally, introduce the display controller driver using code ported
from FreeBSD under its original license terms. Note that this driver
lacks EDID support and is currently hardcoded to 1360x768.
Update the linker script memory layout to utilize the full 256 MiB RAM,
excluding the 8 MiB reserved at the top of memory for the framebuffer.
Signed-off-by: Lwazi Dube <lwazeh@gmail.com>