Add -Wno-unused-parameter

GCC 4.8 emits more warnings.

BUG: 10726440

(cherry picked from commit ff68988ec79b42c6673008b968f0ae89036c38ef)

Change-Id: I68c7aad6c07c2c440122e54791ea82eb07a2163b
camera: HAL3: don't treat all warnings as errors
Silence compiler warnings in newer toolchains (gcc 4.8, clang)

Change-Id: I49942c634642b8a3cacf8f9bd217e089b9eb960b
Signed-off-by: Bernhard Rosenkränzer <Bernhard.Rosenkranzer@linaro.org>