package/jemalloc: add riscv support

riscv support has been added in version 4.2.0 with
https://github.com/jemalloc/jemalloc/commit/919e4a0ea92fbbf9b97efdf9f31a3c800f77cd8f

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/jemalloc/Config.in

@@ -7,6 +7,7 @@ config BR2_PACKAGE_JEMALLOC_ARCH_SUPPORTS
 	default y if BR2_or1k
 	default y if BR2_sparc64
 	default y if BR2_powerpc
+	default y if BR2_riscv
 	default y if BR2_sh4 || BR2sh4eb || BR2_sh4a || BR2_sh4aeb
 
 config BR2_PACKAGE_JEMALLOC