davinci machines: udate davinci targets to latest staging kernels

davinci machines: udate davinci targets to latest staging kernels

- dm355-evm, dm365-evm, dm6446-evm, dm6467-evm, dm6467t-evm
- 2.6.32rc2 - davinci1 staging (PSP 3.01.00.28 - Rel 3.1.0 Phase 3 Build 28i)
  - 7b2683fd0168df1576fcea947ef9f63e905de807
- Add uboot to image depends (EXTRA_IMAGEDEPENDS)
- defconfigs taken from davinci staging tree
  - dm355-evm - davinci_dm355_defconfig
  - dm365-evm - davinci_dm365_defconfig
  - dm6446-evm - davinci_dm644x_defconfig
  - dm6467-evm - davinci_dm646x_defconfig
  - dm6467t-evm - davinci_dm646x_1ghz_defconfig
- Bump kernel PR (davinci.inc)