[POWERPC] Only use H_BULK_REMOVE if the firmware supports it

The previous patch changing pSeries to use H_BULK_REMOVE broke the
JS20 blade, where the firmware doesn't support H_BULK_REMOVE.  This
adds a firmware check so that on machines that don't have H_BULK_REMOVE,
we just use the H_REMOVE call as before.

Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/include/asm-powerpc/firmware.h b/include/asm-powerpc/firmware.h
index abba808..3671c12 100644
--- a/include/asm-powerpc/firmware.h
+++ b/include/asm-powerpc/firmware.h
@@ -44,6 +44,7 @@
 #define FW_FEATURE_LPAR		ASM_CONST(0x0000000000400000)
 #define FW_FEATURE_PS3_LV1	ASM_CONST(0x0000000000800000)
 #define FW_FEATURE_BEAT		ASM_CONST(0x0000000001000000)
+#define FW_FEATURE_BULK_REMOVE	ASM_CONST(0x0000000002000000)
 
 #ifndef __ASSEMBLY__