firmware: tegra: Add stubs when BPMP not enabled

Add static inline stubs to bpmp.h when CONFIG_BPMP is not enabled.
This allows building BPMP-related drivers with COMPILE_TEST.
Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

include/soc/tegra/bpmp.h

@@ -96,9 +96,6 @@ struct tegra_bpmp {
 	struct genpd_onecell_data genpd;
 };
 
-struct tegra_bpmp *tegra_bpmp_get(struct device *dev);
-void tegra_bpmp_put(struct tegra_bpmp *bpmp);
-
 struct tegra_bpmp_message {
 	unsigned int mrq;
 
@@ -114,6 +111,9 @@ struct tegra_bpmp_message {
 	} rx;
 };
 
+#if IS_ENABLED(CONFIG_TEGRA_BPMP)
+struct tegra_bpmp *tegra_bpmp_get(struct device *dev);
+void tegra_bpmp_put(struct tegra_bpmp *bpmp);
 int tegra_bpmp_transfer_atomic(struct tegra_bpmp *bpmp,
 			       struct tegra_bpmp_message *msg);
 int tegra_bpmp_transfer(struct tegra_bpmp *bpmp,
@@ -125,6 +125,42 @@ int tegra_bpmp_request_mrq(struct tegra_bpmp *bpmp, unsigned int mrq,
 			   tegra_bpmp_mrq_handler_t handler, void *data);
 void tegra_bpmp_free_mrq(struct tegra_bpmp *bpmp, unsigned int mrq,
 			 void *data);
+#else
+static inline struct tegra_bpmp *tegra_bpmp_get(struct device *dev)
+{
+	return ERR_PTR(-ENOTSUPP);
+}
+static inline void tegra_bpmp_put(struct tegra_bpmp *bpmp)
+{
+}
+static inline int tegra_bpmp_transfer_atomic(struct tegra_bpmp *bpmp,
+					     struct tegra_bpmp_message *msg)
+{
+	return -ENOTSUPP;
+}
+static inline int tegra_bpmp_transfer(struct tegra_bpmp *bpmp,
+				      struct tegra_bpmp_message *msg)
+{
+	return -ENOTSUPP;
+}
+static inline void tegra_bpmp_mrq_return(struct tegra_bpmp_channel *channel,
+					 int code, const void *data,
+					 size_t size)
+{
+}
+
+static inline int tegra_bpmp_request_mrq(struct tegra_bpmp *bpmp,
+					 unsigned int mrq,
+					 tegra_bpmp_mrq_handler_t handler,
+					 void *data)
+{
+	return -ENOTSUPP;
+}
+static inline void tegra_bpmp_free_mrq(struct tegra_bpmp *bpmp,
+				       unsigned int mrq, void *data)
+{
+}
+#endif
 
 #if IS_ENABLED(CONFIG_CLK_TEGRA_BPMP)
 int tegra_bpmp_init_clocks(struct tegra_bpmp *bpmp);