ARM: OMAP2+: hwmod: Use kzalloc for allocating only one element

Use kzalloc(...) rather than kcalloc(1, ...) because the number of
elements we are specifying in this case is 1, so kzalloc would
accomplish the same thing and we can simplify.

Signed-off-by: Kenneth Lee <klee33@uw.edu>
Message-Id: <20220809072050.1733996-1-klee33@uw.edu>
Signed-off-by: Tony Lindgren <tony@atomide.com>