Revert "use toolchain"

This reverts commit a4c78efbb2ada51b399fa7b22404ad5909568932.
Revert "fix compilation error"

This reverts commit 9d0ae0555669ccdab828b9e6b250ad098307daaa.
Revert "update samsung_trebon_defconfig"

This reverts commit 60bfb1cf4bc07a0425d9f1481ed7c046173c18df.
Revert "block: introduce the BFQ-v4 I/O sched for 2.6.38"

This reverts commit 9787881830c96c743e3e9102e9a5549b03ddb81f.
Revert "block: cgroups, kconfig, build bits for BFQ-v4-2.6.38"

This reverts commit 08a929420e241e573abafb6448a5998d80fac4f0.
Revert "block: prepare I/O context code for BFQ-v4 for 2.6.38"

This reverts commit 5b54c266ddd2cb4165b737ec172a7bc78ca17476.