[ARM] pxa: make second argument of clk_add_alias a name instead of the device

[ARM] pxa: make second argument of clk_add_alias a name instead of the device

clk_add_alias is commonly called for platform devices that are not yet
registered in the device tree. Thus the clock alias is associated with
NULL device name. Fix this by passing the device name instead of just
device pointer.

Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Signed-off-by: Eric Miao <eric.miao@marvell.com>