hikey960: fix build issue with CLANG

plat/hisilicon/hikey960/drivers/pwrc/hisi_pwrc.c:290:20:
error: unused function 'hisi_pdc_set_intmask' [-Werror,-Wunused-function]
static inline void hisi_pdc_set_intmask(void *pdc_base_addr,
                   ^
1 error generated.
Makefile:605: recipe for target 'build/hikey960/release/bl31/hisi_pwrc.o' failed
make: *** [build/hikey960/release/bl31/hisi_pwrc.o] Error 1

Signed-off-by: Haojian Zhuang <haojian.zhuang@linaro.org>
1 file changed