ecryptfs: enhancing ecryptfs to be configurable with encryption type

enabled eCryptfs for qcom targets. In addition to the usual
options, a special mode 'aes-xts' was added for qcom ICE hw
encryption

Change-Id: I20c01adc46c977b4a5db0be9ff93384cda14bc56
Signed-off-by: Lina Zarivach <linaz@codeaurora.org>
Signed-off-by: Andrey Markovytch <andreym@codeaurora.org>