ata: fix ARASAN CompactFlash PATA driver dependencies

Make pata_arasan_cf host driver depend on ARCH_SPEAR13XX config
option as ARASAN CompactFlash PATA support is specific to ST
SPEAr13xx SoCs and the driver to work requires suitable device
tree node (or platform device) to be defined.  Additionally
allow the driver build if COMPILE_TEST config option is set.

Cc: Viresh Kumar <viresh.linux@gmail.com>
Cc: Shiraz Hashim <shiraz.hashim@st.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Tejun Heo <tj@kernel.org>