ARM: CSR: PM: fix build error due to undeclared 'THIS_MODULE'

In the new kernel, we will get the following compile error:
arch/arm/mach-prima2/pm.c:141: error: 'THIS_MODULE' undeclared
here (not in a function)
so include module.h head file explicitly

Signed-off-by: Barry Song <baohua.song@csr.com>