media: venus: Mark bufreq_enc with static keyword

Fix the following sparse warning:

hfi_plat_bufs_v6.c:1242:5: warning: symbol 'bufreq_enc' was not declared.
 Should it be static?
Signed-off-by: Zou Wei <zou_wei@huawei.com>
Signed-off-by: Stanimir Varbanov <stanimir.varbanov@linaro.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

drivers/media/platform/qcom/venus/hfi_plat_bufs_v6.c

@@ -1239,8 +1239,8 @@ static int bufreq_dec(struct hfi_plat_buffers_params *params, u32 buftype,
 	return 0;
 }
 
-int bufreq_enc(struct hfi_plat_buffers_params *params, u32 buftype,
-	       struct hfi_buffer_requirements *bufreq)
+static int bufreq_enc(struct hfi_plat_buffers_params *params, u32 buftype,
+		      struct hfi_buffer_requirements *bufreq)
 {
 	enum hfi_version version = params->version;
 	struct enc_bufsize_ops *enc_ops;