!54 configs: change the value of NLS_CODEPAGE_437 from m to y

Merge Pull Request from: @hifi521 
 
#I5JMOU 
If the NLS_CODEPAGE_437.ko does not exist in the bootrom system, but the
vfat filesystem depends on the NLS_CODEPAGE_437 module, the /boot/efi fails
to be mounted.
Change the value of NLS_CODEPAGE_437 from m to y in arch/arm64/configs
/openeuler_defconfig and arch/x86/configs/openeuler_defconfig. 
 
Link:https://gitee.com/openeuler/kernel/pulls/54

 
Reviewed-by: Liu Chao <liuchao173@huawei.com>
Signed-off-by: Xie XiuQi <xiexiuqi@huawei.com>