msm: timer: Enable ARCH_HAS_READ_CURRENT_TIMER for all MSMs

ARCH_HAS_READ_CURRENT_TIMER method should work for all the MSMs
including UP MSMs and shouldn't be restricted to SMP MSMs.

Remove lpj calculation from 7X30 acpuclock driver too.

Change-Id: I78fd6dddca9b37d8fd653d247b142f8c27ea8b5d
Signed-off-by: Trilok Soni <tsoni@codeaurora.org>