sparc32: implement proper LEON support in head_32 (before highmem)

Use PSR to check if the CPU is LEON and jump to
LEON specific code in this case.

Added a few constants to psr.h to increase readability.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Daniel Hellstrom <daniel@gaisler.com>
Cc: Konrad Eisele <konrad@gaisler.com>
diff --git a/arch/sparc/include/asm/psr.h b/arch/sparc/include/asm/psr.h
index b8c0e5f..c02c735 100644
--- a/arch/sparc/include/asm/psr.h
+++ b/arch/sparc/include/asm/psr.h
@@ -35,6 +35,12 @@
 #define PSR_VERS    0x0f000000         /* cpu-version field          */
 #define PSR_IMPL    0xf0000000         /* cpu-implementation field   */
 
+#define PSR_IMPL_SHIFT		28
+#define PSR_IMPL_SHIFTED_MASK	0xf
+
+#define PSR_IMPL_TI		0x4
+#define PSR_IMPL_LEON		0xf
+
 #ifdef __KERNEL__
 
 #ifndef __ASSEMBLY__