ptest.bbclass: fix error on ubuntu host

ptest.bbclass: fix error on ubuntu host

The do_install_ptest_base function uses 'type -t' command to check
whether do_install_ptest is a function and acts correspondingly.

However, the 'type' command is a shell builtin and its behavior is
not all the same across Linux distros. On ubuntu, if we use #!/bin/sh
as the interpreter for the scripts, as in the case of our intermediate
scripts, the '-t' option for the 'type' command is not supported. So
the check always fails and the do_install_ptest function, even if defined,
is not run.

The same problem also applies to the do_configure_ptest_base and the
do_compile_ptest_base functions.

This patch fixes this problem by avoiding using the 'type' builtin command.

[YOCTO #5128]

(From OE-Core rev: d5a4f031b460437e9501e4e65194ce94d3641130)

Signed-off-by: Chen Qi <Qi.Chen@windriver.com>
Signed-off-by: Saul Wold <sgw@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>