media: cadence: increase buffer size in csi2tx_get_resources()

Fixes this compiler warning:

drivers/media/platform/cadence/cdns-csi2tx.c: In function 'csi2tx_get_resources':
drivers/media/platform/cadence/cdns-csi2tx.c:485:63: warning: '%u' directive output may be truncated writing between 1 and 10 bytes into a region of size 8 [-Wformat-truncation=]
  485 |                 snprintf(clk_name, sizeof(clk_name), "pixel_if%u_clk", i);
      |                                                               ^~
drivers/media/platform/cadence/cdns-csi2tx.c:485:54: note: directive argument in the range [0, 4294967294]
  485 |                 snprintf(clk_name, sizeof(clk_name), "pixel_if%u_clk", i);
      |                                                      ^~~~~~~~~~~~~~~~
drivers/media/platform/cadence/cdns-csi2tx.c:485:17: note: 'snprintf' output between 14 and 23 bytes into a destination of size 16
  485 |                 snprintf(clk_name, sizeof(clk_name), "pixel_if%u_clk", i);
      |                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Acked-by: Maxime Ripard <mripard@kernel.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>