populate_sdk_ext.bbclass: No longer needed to clean away conf/sanity_info

populate_sdk_ext.bbclass: No longer needed to clean away conf/sanity_info

Since the sanity_info file has moved from the conf directory to the
cache directory, there is no longer any need to clean it away
explicitly in clean_esdk_builddir() since the whole cache directory is
already cleaned away anyway.

Signed-off-by: Peter Kjellerstedt <peter.kjellerstedt@axis.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>