board: stemmy: Detect board variants and patch DTB

board: stemmy: Detect board variants and patch DTB

This patch scans the cmdline from the Samsung SBL (second stage
bootloader) and stores the parameters board_id=N and lcdtype=N
in order to augment the DTB for different board and LCD types.

We then add a custom ft_board_setup() callback that will inspect
the DTB and patch it using the stored LCD type. At this point
we know which product we are dealing with, so using the passed
board_id we can also print the board variant for diagnostics.

We patch the Codina, Skomer and Kyle DTBs to use the right
LCD type as passed in lcdtype from the SBL.

This also creates an infrastructure for handling any other
Samsung U8500 board variants that may need a slightly augmented
DTB.

Cc: Markuss Broks <markuss.broks@gmail.com>
Cc: Stephan Gerhold <stephan@gerhold.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>