[WIP] kernel/zarch: Fix cscal and zscal #5704

Job	Run time
build (ubuntu-latest, gfortran, cmake)	12m 48s
build (ubuntu-latest, flang, make)	10m 40s
neoverse_build	4m 36s
build (ubuntu-latest, flang, cmake)	9m 28s
build (ubuntu-latest, gfortran, make)	7m 20s
cross_build (alpha, alpha-linux-gnu, TARGET=EV4)	2m 49s
msys2 (UCRT64, int64, Release)	14m 39s
build (macos-latest, gfortran, cmake)	15m 37s
msys2 (UCRT64, int32, Release)	3m 39s
cross_build (mips64el, mips64el-linux-gnuabi64, DYNAMIC_ARCH=1 TARGET=GENERIC)	3m 41s
cross_build (riscv64, riscv64-linux-gnu, TARGET=RISCV64_GENERIC)	2m 46s
msys2 (CLANG64, int32, Release)	5m 41s
build (macos-latest, gfortran, make)	10m 29s
msys2 (CLANG64, int64, Release)	9m 3s
msys2 (UCRT64, int32, None, mingw-w64-ucrt-x86_64, fc)	9m 52s
cross_build (mipsel, mipsel-linux-gnu, TARGET=MIPS1004K)	4m 15s
msys2 (MINGW32, int32, Release)	2m 45s
	2h 10m 8s

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