regmap: Removed compressed cache support

The compressed register cache support has assumptions that make it hard to
cover in testing, mainly that it requires raw registers defaults be
provided. Rather than either address these assumptions or leave it untested
by the forthcoming KUnit tests let's remove it, the use case is quite thin
and there are no current users.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20230324-regcache-lzo-v1-1-08c5d63e2a5e@kernel.org

drivers/base/regmap/Kconfig

@@ -9,11 +9,6 @@ config REGMAP
 	select MDIO_BUS if REGMAP_MDIO
 	bool
 
-config REGCACHE_COMPRESSED
-	select LZO_COMPRESS
-	select LZO_DECOMPRESS
-	bool
-
 config REGMAP_AC97
 	tristate
 

drivers/base/regmap/Makefile

@@ -4,7 +4,6 @@ CFLAGS_regmap.o := -I$(src)
 
 obj-$(CONFIG_REGMAP) += regmap.o regcache.o
 obj-$(CONFIG_REGMAP) += regcache-rbtree.o regcache-flat.o
-obj-$(CONFIG_REGCACHE_COMPRESSED) += regcache-lzo.o
 obj-$(CONFIG_DEBUG_FS) += regmap-debugfs.o
 obj-$(CONFIG_REGMAP_AC97) += regmap-ac97.o
 obj-$(CONFIG_REGMAP_I2C) += regmap-i2c.o

drivers/base/regmap/internal.h

@@ -281,7 +281,6 @@ enum regmap_endian regmap_get_val_endian(struct device *dev,
 					 const struct regmap_config *config);
 
 extern struct regcache_ops regcache_rbtree_ops;
-extern struct regcache_ops regcache_lzo_ops;
 extern struct regcache_ops regcache_flat_ops;
 
 static inline const char *regmap_name(const struct regmap *map)