drivers: clk: msm: Remove gcc flags from clk makefile

We see that due to gcc optimisation, the R0 register is not getting
updated with the correct value when it returns from __calc_values.
Hence, remove the gcc flag "cse-follow-jumps" from O2 level of
optimisation for clk drivers.

Change-Id: I5ed927b5223f191e5cc584ede9b2637b019a899b
Signed-off-by: Abinaya P <abinayap@codeaurora.org>