M76 chip DRI support for ATI Mobility Radeon HD2600

[Denis Lapshin]

--- radeon_drv.old.c    Tue Jul 17 19:54:00 2012
+++ radeon_drv.c        Mon Jul 16 19:24:26 2012
@@ -493,6 +493,8 @@
            CHIP_RV630|RADEON_NEW_MEMMAP},
        {PCI_VENDOR_ATI, PCI_PRODUCT_ATI_RADEON_HD2600_XT,
            CHIP_RV630|RADEON_NEW_MEMMAP},
+    {PCI_VENDOR_ATI, PCI_PRODUCT_ATI_RADEON_HD2600_M76,
+        CHIP_RV630|RADEON_IS_MOBILITY|RADEON_NEW_MEMMAP},
     {PCI_VENDOR_ATI, PCI_PRODUCT_ATI_RADEON_HD3650_M,
            CHIP_RV635|RADEON_IS_MOBILITY|RADEON_NEW_MEMMAP},
        {PCI_VENDOR_ATI, PCI_PRODUCT_ATI_RADEON_HD3650,