drm/bridge: imx93-mipi-dsi: Fix a couple of building warnings

Fix a couple of building warnings on used uninitialized 'best_m' and
'best_n' local variables by initializing 'best_m' to zero and 'best_n'
to UINT_MAX.  This makes compiler happy only.  No functional change.

Fixes: ce62f8ea ("drm/bridge: imx: Add i.MX93 MIPI DSI support")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202311151746.f7u7dzbZ-lkp@intel.com/Signed-off-by: Liu Ying <victor.liu@nxp.com>
Reviewed-by: Robert Foss <rfoss@kernel.org>
Signed-off-by: Robert Foss <rfoss@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20231123051807.3818342-1-victor.liu@nxp.com

drivers/gpu/drm/bridge/imx/imx93-mipi-dsi.c

@@ -226,8 +226,8 @@ dphy_pll_get_configure_from_opts(struct imx93_dsi *dsi,
 	unsigned long fout;
 	unsigned long best_fout = 0;
 	unsigned int fvco_div;
-	unsigned int min_n, max_n, n, best_n;
-	unsigned long m, best_m;
+	unsigned int min_n, max_n, n, best_n = UINT_MAX;
+	unsigned long m, best_m = 0;
 	unsigned long min_delta = ULONG_MAX;
 	unsigned long delta;
 	u64 tmp;