tools: binman: ti_board_cfg: Fix pylint error over 'br'

With a newer pylint, we get a warning that 'br' could be used before
assignment. Fix this by declaring br first as an empty bytearray.

Reviewed-by: Neha Malcom Francis <n-francis@ti.com>
Signed-off-by: Tom Rini <trini@konsulko.com>
1 file changed