tools: binman: Add missing filenames for various x86 rom tests

With recent changes, some x86-specific rom tests of binman fail to
run. Fix it by adding missing filenames in corresponding entries.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

tools/binman/test/30_x86-rom-me-no-desc.dts

@@ -9,6 +9,7 @@
 		end-at-4gb;
 		size = <16>;
 		intel-me {
+			filename = "me.bin";
 			pos-unset;
 		};
 	};

tools/binman/test/31_x86-rom-me.dts

@@ -9,9 +9,11 @@
 		end-at-4gb;
 		size = <0x800000>;
 		intel-descriptor {
+			filename = "descriptor.bin";
 		};
 
 		intel-me {
+			filename = "me.bin";
 			pos-unset;
 		};
 	};

tools/binman/test/32_intel-vga.dts

@@ -8,6 +8,7 @@
 		size = <16>;
 
 		intel-vga {
+			filename = "vga.bin";
 		};
 	};
 };

tools/binman/test/42_intel-fsp.dts

@@ -8,6 +8,7 @@
 		size = <16>;
 
 		intel-fsp {
+			filename = "fsp.bin";
 		};
 	};
 };

tools/binman/test/43_intel-cmc.dts

@@ -8,6 +8,7 @@
 		size = <16>;
 
 		intel-cmc {
+			filename = "cmc.bin";
 		};
 	};
 };