ARM: dts: msm: correct size property of cma in sdxpoorwills

Correct the size property of CMA pool of mem_dump region.

Change-Id: I115b8f92b88f67166679b73bc86b07cb4f09d90d
Signed-off-by: Charan Teja Reddy <charante@codeaurora.org>
Signed-off-by: Mao Jinlong <jinlmao@codeaurora.org>