drm/amd/display: Assign normalized_pix_clk when color depth = 14

In the Linux kernel, the following vulnerability has been resolved:

drm/amd/display: Assign normalized_pix_clk when color depth = 14

[WHY & HOW]

A warning message "WARNING: CPU: 4 PID: 459 at ... /dc_resource.c:3397

calculate_phy_pix_clks+0xef/0x100 [amdgpu]" occurs because the

display_color_depth == COLOR_DEPTH_141414 is not handled. This is

observed in Radeon RX 6600 XT.

It is fixed by assigning pix_clk * (14 * 3) / 24 - same as the rests.

Also fixes the indentation in get_norm_pix_clk.

(cherry picked from commit 274a87eb389f58eddcbc5659ab0b180b37e92775)