[binutils-gdb] Remove regcache_cooked_read_value

[sergiodj+buildbot@sergiodj.net]

*** TEST RESULTS FOR COMMIT 46a45e9d5b067e484971e3972fa3eae0a224324f ***

Author: Simon Marchi <simon.marchi@ericsson.com>
Branch: master
Commit: 46a45e9d5b067e484971e3972fa3eae0a224324f

Remove regcache_cooked_read_value

Remove regcache_cooked_read_value, update callers to use
readable_regcache::cooked_read_value.

gdb/ChangeLog:

	* regcache.h (regcache_cooked_read_value): Remove, update
	callers to use readable_regcache::cooked_read_value.
	* regcache.c (regcache_cooked_read_value): Remove.