vgabios: don't override the compiler ldflags

Fix for building biossums on genericx86-64 machine, due to QA issue:
ERROR: QA Issue: No GNU_HASH in the elf binary:
'.../0.7a-r0/packages-split/biossums/usr/bin/biossums' [ldflags]
caused by overriding LDFLAGS variable to empty value in project's makefile.

In consequence there's missing LDFLAGS settings from bitbake (including
-Wl,--hash-style=gnu, which causes showing this QA).

Signed-off-by: Dariusz Pelowski <dariusz.pelowski@gmail.com>
Signed-off-by: Bruce Ashfield <bruce.ashfield@windriver.com>

recipes-extended/vgabios/biossums_0.7a.bb

@@ -20,6 +20,7 @@ do_configure() {
     # Don't override the compiler or its flags:
     sed 's,^CC,DISABLED_CC,' -i Makefile
     sed 's,^CFLAGS,DISABLED_CFLAGS,' -i Makefile
+    sed 's,^LDFLAGS,DISABLED_LDFLAGS,' -i Makefile
     # Supply the C flags to the compiler:
     sed 's,-o biossums,$(CFLAGS) -o biossums,' -i Makefile
 }