Most superstitous updates to the RAMTROM driver make it more compatibile with the version used by PX4. From David Sidrane

Tiva SSI and board configurations: hange negative Tiva logic CONFIG_SSIx_DISABLE to positive logic CONFIG_TIVA_SSIx.  Add support for SSI2 and SSI3

Tiva:  Add a configuration setting to better distinguish TM4C123 and 129 families.  Reanem tm4c_syscontrol.h to tm4c123_syscontrol.h; rename tm4c129x_syscontrol.h to tm4c129_syscontrol.h

STM32 LTDC: Move ltdc.h from include/nuttx/video to arch/arm/include/stm32; Trivial updates after general review

Memory configuration:

The heap start address of memory region 3 starts at 0xD0000000.
The allocated framebuffer of the layers is addressed up to the end of the memory
region 3.

If the layer pixel format changes e.g. from RGB565 to RGB24, than the memory
configuration must be configured too. Currently an easy memory calculation
is missing for that in Kconfig.

Signed-off-by: Marco Krahl <ocram.lhark@gmail.com>

Signed-off-by: Marco Krahl <ocram.lhark@gmail.com>

Signed-off-by: Marco Krahl <ocram.lhark@gmail.com>

This adds the following ltdc configuration options:
- dither support
- cmap support, is this the right place for CONFIG_FB_CMAP?
- support for extended ltdc interface

Signed-off-by: Marco Krahl <ocram.lhark@gmail.com>

This adds support for initializing of the ltdc controller and the lcd device connected on the stm32f429i-disco. The following methods are provided for the generic fb interface:

- up_fbinitialize
- up_fbgetvplane
- fb_uninitialize

The following methods are provided for the ltdc interface:

- up_ltdcgetlayer

Signed-off-by: Marco Krahl <ocram.lhark@gmail.com>