cmd: env: add "-e" option for handling UEFI variables

"env [print|set] -e" allows for handling uefi variables without
knowing details about mapping to corresponding u-boot variables.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>

MAINTAINERS

@@ -471,6 +471,7 @@ F:	lib/efi*/
 F:	test/py/tests/test_efi*
 F:	test/unicode_ut.c
 F:	cmd/bootefi.c
+F:	cmd/nvedit_efi.c
 F:	tools/file2include.c
 
 FPGA