drm/nouveau/kms/gv100: use static for gv100_disp_core_mthd_[base|sor]

Sparse reports these issues
coregv100.c:27:1: warning: symbol 'gv100_disp_core_mthd_base' was not declared. Should it be static?
coregv100.c:43:1: warning: symbol 'gv100_disp_core_mthd_sor' was not declared. Should it be static?

These variables are only used in coregv100.c.  Single file use
variables should be static, so add static to their storage-class specifier.
Signed-off-by: Tom Rix <trix@redhat.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Signed-off-by: Lyude Paul <lyude@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220422185132.3163248-1-trix@redhat.com

drivers/gpu/drm/nouveau/nvkm/engine/disp/coregv100.c

@@ -23,7 +23,7 @@
 
 #include <subdev/timer.h>
 
-const struct nv50_disp_mthd_list
+static const struct nv50_disp_mthd_list
 gv100_disp_core_mthd_base = {
 	.mthd = 0x0000,
 	.addr = 0x000000,
@@ -39,7 +39,7 @@ gv100_disp_core_mthd_base = {
 	}
 };
 
-const struct nv50_disp_mthd_list
+static const struct nv50_disp_mthd_list
 gv100_disp_core_mthd_sor = {
 	.mthd = 0x0020,
 	.addr = 0x000020,