[binutils-gdb] Remove regcache_raw_read_part

[sergiodj+buildbot@sergiodj.net]

*** TEST RESULTS FOR COMMIT 502fe83eb549476fac09ec62c7fd66447791ba2a ***

Author: Simon Marchi <simon.marchi@ericsson.com>
Branch: master
Commit: 502fe83eb549476fac09ec62c7fd66447791ba2a

Remove regcache_raw_read_part

Remove regcache_raw_read_part, update callers to use
readable_regcache::raw_read_part instead.

gdb/ChangeLog:

	* regcache.h (regcache_raw_read_part): Remove, update callers to
	use readable_regcache::raw_read_part instead.
	* regcache.c (regcache_raw_read_part): Remove.