habanalabs: set non-0 value in dram default page size

Looking forward we will need to report to the user what is the default
page size used.

This will be done more conveniently by explicitly updating the property
rather than to rely on a "0 meaning default" value.

Signed-off-by: Ohad Sharabi <osharabi@habana.ai>
Reviewed-by: Oded Gabbay <ogabbay@kernel.org>
Signed-off-by: Oded Gabbay <ogabbay@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>