Integrate u-boot-seco-imx/ektor5/a62-hdmi-gpu

Commit: arm/nxp/imx/develop/yocto/5.x/u-boot-seco-imx@a6c7b436

[A62][ENV] Add bpp specification to HDMI

This videomode spec is required for GPU to visualize correctly framebuffer accelerated applications.

Signed-off-by: Ettore Chimenti ettore.chimenti@seco.com