drm/i915/dsi: Add some debug logging to mipi_exec_i2c (v2)

Add some debug logging to mipi_exec_i2c, to make debugging various
issues seen with it easier.

Changes in v2:
- Drop unnecessary __func__ drm_dbg_kms() argument
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230920195613.304091-5-hdegoede@redhat.com

drivers/gpu/drm/i915/display/intel_dsi_vbt.c

@@ -565,6 +565,9 @@ static const u8 *mipi_exec_i2c(struct intel_dsi *intel_dsi, const u8 *data)
 	u8 payload_size = *(data + 6);
 	u8 *payload_data;
 
+	drm_dbg_kms(&i915->drm, "bus %d client-addr 0x%02x reg 0x%02x data %*ph\n",
+		    vbt_i2c_bus_num, slave_addr, reg_offset, payload_size, data + 7);
+
 	if (intel_dsi->i2c_bus_num < 0) {
 		intel_dsi->i2c_bus_num = vbt_i2c_bus_num;
 		i2c_acpi_find_adapter(intel_dsi, slave_addr);