qemu: fix build on sh4a and sh4aeb

Qemu doesn't understand sh4a and sh4aeb as separate architectures, it
only knows about sh4 and sh4eb. However, it does support sh4a, since
it emulates the SH7785 CPU which is a SH4A.

Therefore, with this commit, sh4a/sh4aeb are translated as sh4/sh4eb
for Qemu.

Fixes:

  http://autobuild.buildroot.org/results/8f9/8f99a776f35d4ab0841d9fd2db509850ef603bd4/
  and many previous similar build failures

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/qemu/qemu.mk

@@ -38,8 +38,8 @@ HOST_QEMU_DEPENDENCIES = host-pkgconf host-python host-zlib host-libglib2 host-p
 #       sh2a            not supported
 #       sh4             sh4
 #       sh4eb           sh4eb
-#       sh4a            ?
-#       sh4aeb          ?
+#       sh4a            sh4
+#       sh4aeb          sh4eb
 #       sh64            not supported
 #       sparc           sparc
 
@@ -56,6 +56,12 @@ endif
 ifeq ($(HOST_QEMU_ARCH),powerpc)
 HOST_QEMU_ARCH = ppc
 endif
+ifeq ($(HOST_QEMU_ARCH),sh4a)
+HOST_QEMU_ARCH = sh4
+endif
+ifeq ($(HOST_QEMU_ARCH),sh4aeb)
+HOST_QEMU_ARCH = sh4eb
+endif
 HOST_QEMU_TARGETS = $(HOST_QEMU_ARCH)-linux-user
 
 ifeq ($(BR2_PACKAGE_HOST_QEMU),y)