klibc: Mark incompatible with riscv32

klibc only has a riscv64 port, which hardcodes KLIBCBITSIZE = 64 and
uses 64-bit loads and stores in its assembly, and upstream has no
riscv32 port. With KLIBC_ARCH defaulting to TARGET_ARCH, the build fails:

  make[1]: *** No rule to make target '.../usr/klibc/arch/riscv32/MCONFIG'.  Stop.

Mark klibc and the recipes sharing klibc.inc incompatible with riscv32
so they are skipped instead of failing to build.

Also skip all recipes inheriting klibc

AI-Generated: Uses Claude Code
Signed-off-by: Khem Raj <khem.raj@oss.qualcomm.com>

meta-initramfs/classes/klibc.bbclass

@@ -23,3 +23,6 @@ LDFLAGS:append:toolchain-clang:libc-klibc:arm = " --rtlib=libgcc --unwindlib=lib
 LDFLAGS[export] = "1"
 
 OVERRIDES =. "libc-klibc:"
+
+# klibc is not yet ported to riscv32
+COMPATIBLE_HOST:riscv32 = "null"

meta-initramfs/recipes-devtools/klibc/klibc.inc

@@ -78,3 +78,5 @@ KLIBC_ARCH:powerpc = "ppc"
 KLIBC_ARCH:powerpc64 = "ppc64"
 KLIBC_ARCH:powerpc64le = "ppc64"
 THIS_LIBKLIBC = "libklibc (= ${PV}-${PR})"
+
+COMPATIBLE_HOST:riscv32 = "null"