bcma: Replace mdelay with usleep_range in bcma_pmu_resources_init
After checking all possible call chains to bcma_pmu_resources_init() here,
my tool finds that this function is never called in atomic context,
namely never in an interrupt handler or holding a spinlock.
Thus mdelay can be replaced with usleep_range to avoid busy wait.
This is found by a static analysis tool named DCNS written by myself.
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com> Acked-by: Larry Finger <Larry.Finger@lwfinger.net> Signed-off-by: Kalle Valo <kvalo@codeaurora.org>