HSI: Use kcalloc() in hsi_register_board_info()

A multiplication for the size determination of a memory allocation
indicated that an array data structure should be processed.
Thus use the corresponding function "kcalloc".

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>