package/gnu-efi: enable on RISC-V 64-bit
gnu-efi RISC-V 64bit support was introduced in commit [1], first
included in version 3.0.14.
This commit adds this architecture in _ARCH_SUPPORTS.
[1] https://sourceforge.net/p/gnu-efi/code/ci/b95f138fa1550040e68ac3dd34cfce7d148d7984
Signed-off-by: Julien Olivain <ju.o@free.fr>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>