defconfig: msm8953: Turn off slub debug on by default

Due to scm call request, 1 page is allocated frequently.
With slub debug on enabled by default, we will get order 1 pages
increased from order 0.
To avoid the potential issue of alloc pages, turn off the config
by default.

CRs-Fixed: 2252427
Change-Id: Ia70f3934f29fcf8eb6546115cb8021fdd3c95860
Signed-off-by: Zhenhua Huang <zhenhuah@codeaurora.org>