dependencies/debian: Install dependencies for U-Boot

U-Boot build dependencies are listed on their online documentation [1],
but the listed Debian packages also include test-only dependencies.
While installing dependencies, install the packages necessary to build
U-Boot, except for the test-only ones I could identify.

[1] https://u-boot.readthedocs.io/en/latest/build/gcc.html



Signed-off-by: Alper Nebi Yasak <alpernebiyasak@gmail.com>