configure: check for which

Don't use type becuase its not supported in Free BSD AFAICT.

Fixes: tpm2-software#785

Signed-off-by: William Roberts <william.c.roberts@intel.com>

configure.ac

@@ -45,6 +45,7 @@ PKG_CHECK_MODULES([TSS2_SYS],[tss2-sys >= 2.4.0])
 PKG_CHECK_MODULES([TSS2_MU],[tss2-mu])
 PKG_CHECK_MODULES([TSS2_TCTILDR],[tss2-tctildr])
 PKG_CHECK_MODULES([TSS2_RC],[tss2-rc])
+AC_CHECK_PROG([WHICH], [which], [which])
 AC_ARG_VAR([GDBUS_CODEGEN],[The gdbus-codegen executable.])
 AC_CHECK_PROG([GDBUS_CODEGEN], [gdbus-codegen], [gdbus-codegen])
 AS_IF([test ! -x "$(which $GDBUS_CODEGEN)"],