sstate.bbclass: fix sstate_hardcode_path()

sstate.bbclass: fix sstate_hardcode_path()

The "grep -e (x|y)" doesn't work, for example:
$ echo xy | grep -e '(x|y)'
No output

We can use "grep -E" (extended regexp) or "grep -e x -e y" to fix it.
It only affected the cross recipes.

Signed-off-by: Robert Yang <liezhi.yang@windriver.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>