MIPS: compressed: Fix build with ZSTD compression

Fix the following build issues:

mips64el-linux-ld: arch/mips/boot/compressed/decompress.o: in function `FSE_buildDTable_internal':
decompress.c:(.text.FSE_buildDTable_internal+0x2cc): undefined reference to `__clzdi2'
mips64el-linux-ld: arch/mips/boot/compressed/decompress.o: in function `BIT_initDStream':
decompress.c:(.text.BIT_initDStream+0x7c): undefined reference to `__clzdi2'
mips64el-linux-ld: decompress.c:(.text.BIT_initDStream+0x158): undefined reference to `__clzdi2'
mips64el-linux-ld: arch/mips/boot/compressed/decompress.o: in function `ZSTD_buildFSETable_body_default.constprop.0':
decompress.c:(.text.ZSTD_buildFSETable_body_default.constprop.0+0x2a8): undefined reference to `__clzdi2'
mips64el-linux-ld: arch/mips/boot/compressed/decompress.o: in function `FSE_readNCount_body_default':
decompress.c:(.text.FSE_readNCount_body_default+0x130): undefined reference to `__ctzdi2'
mips64el-linux-ld: decompress.c:(.text.FSE_readNCount_body_default+0x1a4): undefined reference to `__ctzdi2'
mips64el-linux-ld: decompress.c:(.text.FSE_readNCount_body_default+0x2e4): undefined reference to `__clzdi2'
mips64el-linux-ld: arch/mips/boot/compressed/decompress.o: in function `HUF_readStats_body_default':
decompress.c:(.text.HUF_readStats_body_default+0x184): undefined reference to `__clzdi2'
mips64el-linux-ld: decompress.c:(.text.HUF_readStats_body_default+0x1b4): undefined reference to `__clzdi2'
mips64el-linux-ld: arch/mips/boot/compressed/decompress.o: in function `ZSTD_DCtx_getParameter':
decompress.c:(.text.ZSTD_DCtx_getParameter+0x60): undefined reference to `__clzdi2'

Fixes: a510b616131f ("MIPS: Add support for ZSTD-compressed kernels")
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Nick Terrell <terrelln@fb.com>
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>