tcg/sparc64: Rename from tcg/sparc

Emphasize that we only support full 64-bit code generation.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
diff --git a/meson.build b/meson.build
index 1c1afcc..d809d51 100644
--- a/meson.build
+++ b/meson.build
@@ -49,7 +49,7 @@
 bsd_oses = ['gnu/kfreebsd', 'freebsd', 'netbsd', 'openbsd', 'dragonfly', 'darwin']
 supported_oses = ['windows', 'freebsd', 'netbsd', 'openbsd', 'darwin', 'sunos', 'linux']
 supported_cpus = ['ppc', 'ppc64', 's390x', 'riscv', 'x86', 'x86_64',
-  'arm', 'aarch64', 'loongarch64', 'mips', 'mips64', 'sparc', 'sparc64']
+  'arm', 'aarch64', 'loongarch64', 'mips', 'mips64', 'sparc64']
 
 cpu = host_machine.cpu_family()
 
@@ -469,8 +469,6 @@
   endif
   if get_option('tcg_interpreter')
     tcg_arch = 'tci'
-  elif host_arch == 'sparc64'
-    tcg_arch = 'sparc'
   elif host_arch == 'x86_64'
     tcg_arch = 'i386'
   elif host_arch == 'ppc64'