ARM: 7492/1: add strstr declaration for decompressors

With the generic unaligned.h, more kernel headers get pulled in including
dynamic_debug.h which needs strstr. As it is not really used, we only need
a declaration here.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Tested-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Merge pull request #235 from P33M/rpi-3.6.y

dwc_otg: fix potential use-after-free case in interrupt handler
fix missing modulo for bit in bank computation, in bcm2708 gpio irq mask
Merge pull request #240 from Sagittarii/gpio_irg_fix

fix missing modulo for bit in bank computation, in bcm2708 gpio irq mask