disp: msm: sde: remove static access specifier for sde_dbg_base

In DLKM builds, all the display symbols are included as part
of msm_drm.ko and symbols are dynamically linked while
loading ramdumps. This change removes static specifier for
sde_dbg_base in order to access the variable from ramparser
and extract the required logs with the help of ramparser
tool and also in automation stability runs.

Change-Id: I3eae0bc9db3bd285642bf9f7930a31ab47c446e3
Signed-off-by: Yashwanth <yvulapu@codeaurora.org>