parisc: Fix build of compressed kernel even with debug enabled

With debug info enabled (CONFIG_DEBUG_INFO=y) the resulting vmlinux may get
that huge that we need to increase the start addresss for the decompression
text section otherwise one will face a linker error.
Reported-by: Sven Schnelle <svens@stackframe.org>
Tested-by: Sven Schnelle <svens@stackframe.org>
Cc: stable@vger.kernel.org # v4.14+
Signed-off-by: Helge Deller <deller@gmx.de>

arch/parisc/boot/compressed/vmlinux.lds.S

@@ -48,8 +48,8 @@ SECTIONS
 		*(.rodata.compressed)
 	}
 
-	/* bootloader code and data starts behind area of extracted kernel */
-	. = (SZ_end - SZparisc_kernel_start + KERNEL_BINARY_TEXT_START);
+	/* bootloader code and data starts at least behind area of extracted kernel */
+	. = MAX(ABSOLUTE(.), (SZ_end - SZparisc_kernel_start + KERNEL_BINARY_TEXT_START));
 
 	/* align on next page boundary */
 	. = ALIGN(4096);