riscv: enable CD-ROM file systems in defconfig

CD-ROM images are still commonly used for installer images and other
data exchange.

These file systems should be supported on RISC-V by default
like they are on x86_64.
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Link: https://lore.kernel.org/r/20220812200853.311474-1-heinrich.schuchardt@canonical.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

arch/riscv/configs/defconfig

@@ -166,6 +166,9 @@ CONFIG_BTRFS_FS=m
 CONFIG_BTRFS_FS_POSIX_ACL=y
 CONFIG_AUTOFS4_FS=y
 CONFIG_OVERLAY_FS=m
+CONFIG_ISO9660_FS=y
+CONFIG_JOLIET=y
+CONFIG_ZISOFS=y
 CONFIG_MSDOS_FS=y
 CONFIG_VFAT_FS=y
 CONFIG_TMPFS=y