mwifiex: update pcie8766 scratch register addresses

The scratch register addresses have been changed for newer chips.
Since the old chip was never shipped and it will not be supported
any more, just update register addresses to support the new chips.

Cc: <stable@vger.kernel.org> # 3.2.y, 3.3.y
Signed-off-by: Bing Zhao <bzhao@marvell.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>