drm/i915/xe3p_lpd: use pixel normalizer for fp16 formats for FBC

drm/i915/xe3p_lpd: use pixel normalizer for fp16 formats for FBC

There is a hw restriction that we could enable the FBC for FP16
formats only if the pixel normalization block is enabled. Hence
enable the pixel normalizer block with normalzation factor as
1.0 for the supported FP16 formats to get the FBC enabled. Two
existing helper function definitions are moved up to avoid the
forward declarations as part of this patch as well.

v2: sw/hw state differentiation on handling pixel normalizer (Jani)

Bspec: 69863, 68881
Cc: Shekhar Chauhan <shekhar.chauhan@intel.com>
Signed-off-by: Vinod Govindapillai <vinod.govindapillai@intel.com>
Signed-off-by: Gustavo Sousa <gustavo.sousa@intel.com>
Reviewed-by: Uma Shankar <uma.shankar@intel.com>
Link: https://patch.msgid.link/20251027134001.325064-5-vinod.govindapillai@intel.com