drm/msm/sde: Change the interrupt status flag to non static

g_sde_irq_status saves the status of the interrupt for
debugging interrupt storm cases. Ramdumps collected do not
have the corresponding symbol as it is defined as static
variable. Hence change to non static variable.

Change-Id: I539c0144667ad7e5cdb51ae9c73133cedcc4ca29
Signed-off-by: Lakshmi Narayana Kalavala <lkalaval@codeaurora.org>
Signed-off-by: Abhijith Desai <desaia@codeaurora.org>