build: Fix ARM ISA detection
armv7 isn't a real cpu_family in meson, so drop that. The detection for __ARM_ARCH_ISA_ARM was also inverted.
Fixes: #6 (closed)
armv7 isn't a real cpu_family in meson, so drop that. The detection for __ARM_ARCH_ISA_ARM was also inverted.
Fixes: #6 (closed)