drm/amdgpu/swsmu: fix ARC build errors

We want to use the dev_* functions here rather than the pr_* variants.
Switch to using dev_warn() which mirrors what we do on other asics.

Fixes the following build errors on ARC:

../drivers/gpu/drm/amd/amdgpu/../powerplay/navi10_ppt.c: In function 'navi10_fill_i2c_req':
../arch/arc/include/asm/bug.h:24:2: error: implicit declaration of function 'pr_warn'; did you mean 'drm_warn'? [-Werror=implicit-function-declaration]

../drivers/gpu/drm/amd/amdgpu/../powerplay/sienna_cichlid_ppt.c: In function 'sienna_cichlid_fill_i2c_req':
../arch/arc/include/asm/bug.h:24:2: error: implicit declaration of function 'pr_warn'; did you mean 'drm_warn'? [-Werror=implicit-function-declaration]

Reported-by: kernel test robot <[e-mail]>
Cc: Randy Dunlap <[e-mail]>
Cc: Evan Quan <[e-mail]>
Cc: Vineet Gupta <[e-mail]>
Cc: [e-mail]
Acked-by: Randy Dunlap <[e-mail]>
Signed-off-by: Alex Deucher <[e-mail]>

drivers/gpu/drm/amd/powerplay/navi10_ppt.c

···
 {
 	int i;
 
-	BUG_ON(numbytes > MAX_SW_I2C_COMMANDS);
-
 	req->I2CcontrollerPort = 0;
 	req->I2CSpeed = 2;
 	req->SlaveAddress = address;
···
 	struct smu_table_context *smu_table = &adev->smu.smu_table;
 	struct smu_table *table = &smu_table->driver_table;
 
+	if (numbytes > MAX_SW_I2C_COMMANDS) {
+		dev_err(adev->dev, "numbytes requested %d is over max allowed %d\n",
+			numbytes, MAX_SW_I2C_COMMANDS);
+		return -EINVAL;
+	}
+
 	memset(&req, 0, sizeof(req));
 	navi10_fill_i2c_req(&req, false, address, numbytes, data);
 
···
 	uint32_t ret;
 	SwI2cRequest_t req;
 	struct amdgpu_device *adev = to_amdgpu_device(control);
+
+	if (numbytes > MAX_SW_I2C_COMMANDS) {
+		dev_err(adev->dev, "numbytes requested %d is over max allowed %d\n",
+			numbytes, MAX_SW_I2C_COMMANDS);
+		return -EINVAL;
+	}
 
 	memset(&req, 0, sizeof(req));
 	navi10_fill_i2c_req(&req, true, address, numbytes, data);

drivers/gpu/drm/amd/powerplay/sienna_cichlid_ppt.c

···
 {
 	int i;
 
-	BUG_ON(numbytes > MAX_SW_I2C_COMMANDS);
-
 	req->I2CcontrollerPort = 0;
 	req->I2CSpeed = 2;
 	req->SlaveAddress = address;
···
 	struct smu_table_context *smu_table = &adev->smu.smu_table;
 	struct smu_table *table = &smu_table->driver_table;
 
+	if (numbytes > MAX_SW_I2C_COMMANDS) {
+		dev_err(adev->dev, "numbytes requested %d is over max allowed %d\n",
+			numbytes, MAX_SW_I2C_COMMANDS);
+		return -EINVAL;
+	}
+
 	memset(&req, 0, sizeof(req));
 	sienna_cichlid_fill_i2c_req(&req, false, address, numbytes, data);
 
···
 	uint32_t ret;
 	SwI2cRequest_t req;
 	struct amdgpu_device *adev = to_amdgpu_device(control);
+
+	if (numbytes > MAX_SW_I2C_COMMANDS) {
+		dev_err(adev->dev, "numbytes requested %d is over max allowed %d\n",
+			numbytes, MAX_SW_I2C_COMMANDS);
+		return -EINVAL;
+	}
 
 	memset(&req, 0, sizeof(req));
 	sienna_cichlid_fill_i2c_req(&req, true, address, numbytes, data);