msm8x60: Fix crash when bringing up cpu1 from userspace.

When cpu1 is brought up by writing to sys/devices/system/cpu/cpu1/online,
acpuclk_8x60_set_rate() is called from cpu0.  This triggers an error in
msm_spm_set_vdd() which leads to a crash and reboot.

Fix this by rescheduling on the correct CPU when necessary.