xe/oa: Drop the unused logic to parse context image

Now that all register configurations are using MI_LOAD_REGISTER_IMM,
drop the logic to parse context image for offset.

v2: Remove unused lrc headers (Ashutosh)

Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Reviewed-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Reviewed-by: Jonathan Cavitt <jonathan.cavitt@intel.com>
Signed-off-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241220171919.571528-3-umesh.nerlige.ramappa@intel.com