fix module_param mistake in it821x

The attached patch fixes a trivial
mistake in a MODULE_PARAM_DESC of pata_it821x
driver. The parameter name in MODULE_PARAM_DESC
should match the one in module_param_named.

Signed-off-by: Stas Sergeev <stsp@aknet.ru>
Signed-off-by: Jeff Garzik <jeff@garzik.org>