[WIP] kernel/zarch: Fix cscal and zscal #5685

Job	Run time
neoverse_build	5m 23s
msys2 (UCRT64, int64, Release)	13m 51s
msys2 (UCRT64, int32, Release)	12m 46s
msys2 (MINGW32, int32, Release)	15m 47s
msys2 (CLANG64, int32, Release)	15m 39s
build (ubuntu-latest, gfortran, make)	22m 3s
build (ubuntu-latest, flang, make)	5m 19s
build (macos-latest, gfortran, cmake)	12m 5s
msys2 (CLANG64, int64, Release)	16m 15s
cross_build (riscv64, riscv64-linux-gnu, TARGET=RISCV64_GENERIC)	2m 45s
msys2 (UCRT64, int32, None, mingw-w64-ucrt-x86_64, fc)	11m 14s
build (ubuntu-latest, gfortran, cmake)	44m 37s
build (macos-latest, gfortran, make)	3m 10s
build (ubuntu-latest, flang, cmake)	9m 56s
cross_build (mips64el, mips64el-linux-gnuabi64, DYNAMIC_ARCH=1 TARGET=GENERIC)	3m 51s
cross_build (alpha, alpha-linux-gnu, TARGET=EV4)	2m 36s
cross_build (mipsel, mipsel-linux-gnu, TARGET=MIPS1004K)	4m 36s
	3h 21m 53s

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