msm: camera: config: Fix lahaina configuration

Top-level Makefile doesn't export techpack configs.
As such, we must revert to generating our own conf.h file instead of
relying on autoconf.h. This has the side-effect of not allowing
IS_REACHABLE/IS_ENABLED macro's from working on configs enabled within
a techpack.

CRs-Fixed: 2584631
Change-Id: I9c35b305b81c5a6a6892ca87ace9f69192fcca5b
Signed-off-by: Karthik Jayakumar <kjayakum@codeaurora.org>

Makefile

@@ -32,6 +32,11 @@ LINUXINCLUDE    += \
 		-include $(srctree)/techpack/camera/config/bengalcameraconf.h
 endif
 
+ifeq ($(CONFIG_ARCH_LAHAINA), y)
+LINUXINCLUDE    += \
+		-include $(srctree)/techpack/camera/config/lahainacameraconf.h
+endif
+
 ifneq (,$(filter $(CONFIG_SPECTRA_CAMERA), y m))
 # Use USERINCLUDE when you must reference the UAPI directories only.
 USERINCLUDE     += \