meson.build: drop duplicate 'sparc64' entry

CC: Laurent Vivier <laurent@vivier.eu>
CC: qemu-trivial@nongnu.org
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org>
Message-Id: <20201012175719.2573367-1-slyfox@gentoo.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>

meson.build

@@ -41,7 +41,7 @@ have_block = have_system or have_tools
 python = import('python').find_installation()
 
 supported_oses = ['windows', 'freebsd', 'netbsd', 'openbsd', 'darwin', 'sunos', 'linux']
-supported_cpus = ['ppc', 'ppc64', 's390x', 'sparc64', 'riscv32', 'riscv64', 'x86', 'x86_64',
+supported_cpus = ['ppc', 'ppc64', 's390x', 'riscv32', 'riscv64', 'x86', 'x86_64',
   'arm', 'aarch64', 'mips', 'mips64', 'sparc', 'sparc64']
 
 cpu = host_machine.cpu_family()