ARM: dts: msm: Add the NOM_L1 power level to acd table

Include NOM_L1 in acd table as the highest supported GPU power level
supported in A640.

Change-Id: Ia9a627a9b329a105eb98528d351272c0f8a1d7bc
Signed-off-by: Mohammed Mirza Mandayappurath Manzoor <mmandaya@codeaurora.org>