mwifiex: shorten the host sleep configuration macro names

As we are adding a few more macros in this category in next
patch, this cleanup work is required.

Signed-off-by: Amitkumar Karwar <akarwar@marvell.com>
Signed-off-by: Bing Zhao <bzhao@marvell.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>