clk: msm: Select appropriate clock flags for 32-bit

1. Select COMMON_CLK_MSM for msmfalcon when building
for 32-bit.
2. Select RATIONAL when COMMON_CLK_MSM is selected as
it's using an api from rational library.

Change-Id: I5b8fa962718a5ae44dfd18a13285715580ee0dbc
Signed-off-by: Srinivas Ramana <sramana@codeaurora.org>