qcom: idle-v8: miscellaneous bug fixes

Make the msm_pm_boot_vector aligned for 64bit.
msm_pm_boot_vector contains the physical address of the warmboot
function and corresponds to a 64 bit address on v8 architectures.
Fix address arithmetic to account for 64 bit.

Change-Id: I30e07b275ba66d5edf24ac586d81cff9cd88560d
Signed-off-by: Anji Jonnala <anjir@codeaurora.org>