package/crun: needs MMU

Fix the following build failure with uclibc but without MMU raised since
commit 223596c75d73a7eb29152235d3c5d9bf53bd58f5:

/home/autobuild/autobuild/instance-6/output-1/host/riscv64-buildroot-linux-uclibc/bin/ld.real: ./.libs/libcrun.a(libcrun_la-container.o): in function `.L0 ':
container.c:(.text+0x4e7c): undefined reference to `fork'

Fixes:
 - http://autobuild.buildroot.org/results/f19482753e9262ec806cf550619170467a144daf

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>

package/crun/Config.in

@@ -1,5 +1,6 @@
 config BR2_PACKAGE_CRUN
 	bool "crun"
+	depends on BR2_USE_MMU # fork()
 	depends on BR2_TOOLCHAIN_GCC_AT_LEAST_4_9 # C11/stdatomic.h
 	select BR2_PACKAGE_ARGP_STANDALONE if !BR2_TOOLCHAIN_USES_GLIBC
 	select BR2_PACKAGE_YAJL # libocispec
@@ -9,5 +10,6 @@ config BR2_PACKAGE_CRUN
 	  https://github.com/containers/crun
 
 comment "crun needs a glibc or musl toolchain, gcc >= 4.9"
+	depends on BR2_USE_MMU
 	depends on BR2_TOOLCHAIN_USES_UCLIBC || \
 		!BR2_TOOLCHAIN_GCC_AT_LEAST_4_9