Bug#1059606: fwupd: add build support for loongarch64

[zhangdandan <zhangdandan@loongson.cn>]

Source: fwupd
Version: 1.9.10-1
Severity: wishlist
Tags: patch ftbfs
User: debian-loongarch@lists.debian.org
Usertags: loong64

Dear maintainers,

Compiling the fwupd failed for loong64 in the my local loong64 environment.
Referring to other architectures, maybe we need to add build support for 
loongarch64 (drop valgrind build dependency for loong64).
```
debian/control
- valgrind [!ia64 !riscv64 !x32 !mips !sparc64 !sh4 !ppc64 !powerpcspe 
!hppa !alpha !mips64el !armhf !armel !mipsel !m68k],
+ valgrind [!ia64 !riscv64 !x32 !mips !sparc64 !sh4 !ppc64 !powerpcspe 
!hppa !alpha !mips64el !armhf !armel !mipsel !m68k !loong64],
```

With the above change in d/control, the fwupd source package was 
compiled successfully on my local loong64 rootfs environment.
Please review whether the above modifications are correct. Your opinions 
are welcome.

thanks,
Dandan Zhang