kconfig: remove P_ENV property type

This property is not set by anyone since commit 104daea149 ("kconfig:
reference environment variables directly and remove 'option env='").

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>

scripts/kconfig/qconf.cc

@@ -1149,7 +1149,6 @@ QString ConfigInfoView::debug_info(struct symbol *sym)
 		case P_DEFAULT:
 		case P_SELECT:
 		case P_RANGE:
-		case P_ENV:
 			debug += prop_get_type_name(prop->type);
 			debug += ": ";
 			expr_print(prop->expr, expr_print_help, &debug, E_NONE);