drm/i915/bios: Define VBT block 57 (Vswing PreEmphasis Table) contents

Define the contents of VBT block 57 (Vswing PreEmphasis Table).

The contents is highly platform specific. The columns of the
table corresponding to some set of PHY/etc registers. The rows
corresponding to all legal vswing+pre-emphasis combinations
(ie. should be 10 rows in each table). And each table
corresponds to a platform specific (mostly undocumented)
mapping based on link rate/eDP low-vswing/etc. parameters.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240503122449.27266-32-ville.syrjala@linux.intel.comReviewed-by: Jani Nikula <jani.nikula@intel.com>

drivers/gpu/drm/i915/display/intel_vbt_defs.h

@@ -184,6 +184,7 @@ enum bdb_block_id {
 	BDB_MIPI_SEQUENCE		= 53, /* 177+ */
 	BDB_RGB_PALETTE			= 54, /* 180+ */
 	BDB_COMPRESSION_PARAMETERS	= 56, /* 213+ */
+	BDB_VSWING_PREEMPH		= 57, /* 218+ */
 	BDB_GENERIC_DTD			= 58, /* 229+ */
 	BDB_SKIP			= 254, /* VBIOS only */
 };
@@ -1481,6 +1482,16 @@ struct bdb_compression_parameters {
 	struct dsc_compression_parameters_entry data[16];
 } __packed;
 
+/*
+ * Block 57 -  Vswing PreEmphasis Table
+ */
+
+struct bdb_vswing_preemph {
+	u8 num_tables;
+	u8 num_columns;
+	u32 tables[];
+} __packed;
+
 /*
  * Block 58 - Generic DTD Block
  */