icu: set ac_cv_path_install to ensure install tool reproducibility

icu: set ac_cv_path_install to ensure install tool reproducibility

icu will check program install path during do_configure, eg:
checking for a BSD-compatible install... /path/to/install -c

And this path will be writen into pkgdata.inc:
INSTALL_CMD=$(INSTALL-L)

Decided by if install is installed into recipe-sysroot-native during
do_configure stage, the INSTALL_CMD could be
/build/tmp/work/corei7-64-wrs-linux/icu/76-1/recipe-sysroot-native/usr/bin/install
or /build/tmp/hosttools/install if the build is rerun after the sysroot was
extended.

set ac_cv_path_install to install under hosttools to make a deterministic
result of INSTALL_CMD, avoid vary caused by the execute sequence of
another task which DEPENDS on coreutils-native and independent with
do_configure

[RP: Removed paths from ac_cv_path_install to simplify and avoid QA error too]
Signed-off-by: Changqing Li <changqing.li@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>