drm/tegra: firewall: Check for is_addr_reg existence in IMM check

In the IMM opcode check, don't call is_addr_reg if it's not set.

Fixes: 8cc95f3f ("drm/tegra: Add job firewall")
Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

drivers/gpu/drm/tegra/firewall.c

@@ -97,6 +97,9 @@ static int fw_check_regs_imm(struct tegra_drm_firewall *fw, u32 offset)
 {
 	bool is_addr;
 
+	if (!fw->client->ops->is_addr_reg)
+		return 0;
+
 	is_addr = fw->client->ops->is_addr_reg(fw->client->base.dev, fw->class,
 					       offset);
 	if (is_addr)