config: qemu: increase SYS_MALLOC_F_LEN

Several configutation options require additional memory before relocation:

* CONSOLE_RECORD
* LOG
* RSA

The current default of 0x400 is too small to encompass them all. Increase
the value of SYS_MALLOC_F_LEN to 0x2000 for ARCH_QEMU.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
diff --git a/Kconfig b/Kconfig
index 0e7ccc0..8f3fba0 100644
--- a/Kconfig
+++ b/Kconfig
@@ -146,7 +146,7 @@
 	default 0x2000 if (ARCH_IMX8 || ARCH_IMX8M || ARCH_MX7 || \
 			   ARCH_MX7ULP || ARCH_MX6 || ARCH_MX5 || \
 			   ARCH_LS1012A || ARCH_LS1021A || ARCH_LS1043A || \
-			   ARCH_LS1046A)
+			   ARCH_LS1046A || ARCH_QEMU)
 	default 0x400
 	help
 	  Before relocation, memory is very limited on many platforms. Still,