input: evdev: daisy-chain header and client buffers

The evdev driver calculates memory required to hold
client data using power-of-2 math, and then adds header
size, which pushes the request over the power of 2 and
requires 2x larger allocation.

Change the logic to daisy-chain the header and client array.
That way instead of single order4 allocation, we will make
order0+order2.

Signed-off-by: Igor Kovalenko <cik009@motorola.com>
SLT-Approved: Slta Waiver <sltawvr@motorola.com>
Tested-by: Jira Key <jirakey@motorola.com>
Reviewed-by: Christopher Fries <qcf001@motorola.com>
Reviewed-by: Jason Hrycay <jason.hrycay@motorola.com>
Reviewed-by: Klocwork kwcheck <klocwork-kwcheck@sourceforge.mot.com>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>