parisc: Fix KBUILD_IMAGE for self-extracting kernel

Default KBUILD_IMAGE to $(boot)/bzImage if a self-extracting
(CONFIG_PARISC_SELF_EXTRACT=y) kernel is to be built.
This fixes the bindeb-pkg make target.

Signed-off-by: Helge Deller <deller@gmx.de>
Cc: <stable@vger.kernel.org> # v4.14+

arch/parisc/Makefile

@@ -15,7 +15,12 @@
 # Mike Shaver, Helge Deller and Martin K. Petersen
 #
 
+ifdef CONFIG_PARISC_SELF_EXTRACT
+boot := arch/parisc/boot
+KBUILD_IMAGE := $(boot)/bzImage
+else
 KBUILD_IMAGE := vmlinuz
+endif
 
 NM		= sh $(srctree)/arch/parisc/nm
 CHECKFLAGS	+= -D__hppa__=1