plugins: set executable bit on .so files

For historical reasons, some tools like rpm [1] or ldd [2,3]
may expect the executable bit to be present for the correct
identification of shared libraries. The executable bit on .so
files is set by default by compilers (e.g., GCC). It is not
strictly necessary but primarily a convention.

[1] https://docs.fedoraproject.org/en-US/package-maintainers/CommonRpmlintIssues/#unstripped_binary_or_object
[2] https://sourceware.org/git/?p=glibc.git;a=blob;f=elf/ldd.bash.in;h=d6b640df;hb=HEAD#l154

[3] $ sudo ldd /usr/lib/criu/*.so
/usr/lib/criu/amdgpu_plugin.so:
ldd: warning: you do not have execution permission for `/usr/lib/criu/amdgpu_plugin.so'
	linux-vdso.so.1 (0x00007fd0a2a3e000)
	libdrm.so.2 => /lib64/libdrm.so.2 (0x00007fd0a29eb000)
	libdrm_amdgpu.so.1 => /lib64/libdrm_amdgpu.so.1 (0x00007fd0a29de000)
	libc.so.6 => /lib64/libc.so.6 (0x00007fd0a27fc000)
	/lib64/ld-linux-x86-64.so.2 (0x00007fd0a2a40000)
/usr/lib/criu/cuda_plugin.so:
ldd: warning: you do not have execution permission for `/usr/lib/criu/cuda_plugin.so'
	linux-vdso.so.1 (0x00007f1806e13000)
	libc.so.6 => /lib64/libc.so.6 (0x00007f1806c08000)
	/lib64/ld-linux-x86-64.so.2 (0x00007f1806e15000)

Signed-off-by: Radostin Stoyanov <[email protected]>

plugins/amdgpu/Makefile

@@ -54,7 +54,7 @@ install:
 ifeq ($(CONFIG_AMDGPU),y)
 	$(Q) mkdir -p $(DESTDIR)$(PLUGINDIR)
 	$(E) "  INSTALL " $(PLUGIN_NAME)
-	$(Q) install -m 644 $(PLUGIN_SOBJ) $(DESTDIR)$(PLUGINDIR)
+	$(Q) install -m 755 $(PLUGIN_SOBJ) $(DESTDIR)$(PLUGINDIR)
 endif
 .PHONY: install
 

plugins/cuda/Makefile

@@ -31,11 +31,10 @@ mrproper: clean
 install:
 	$(Q) mkdir -p $(DESTDIR)$(PLUGINDIR)
 	$(E) "  INSTALL " $(PLUGIN_NAME)
-	$(Q) install -m 644 $(PLUGIN_SOBJ) $(DESTDIR)$(PLUGINDIR)
+	$(Q) install -m 755 $(PLUGIN_SOBJ) $(DESTDIR)$(PLUGINDIR)
 .PHONY: install
 
 uninstall:
 	$(E) " UNINSTALL" $(PLUGIN_NAME)
 	$(Q) $(RM) $(DESTDIR)$(PLUGINDIR)/$(PLUGIN_SOBJ)
 .PHONY: uninstall
-