efi_loader: Fix warning in efi_gop

Commit ca9193d2b16 ("efi_loader: gop: fixes for CONFIG_DM_VIDEO without
CONFIG_LCD") dropped the explicit (void*) cast for fb_base in efi gop support
for CONFIG_LCD without DM. This patch adds it back, eliminating the now occuring
warning again

Fixes: ca9193d2b16 ("efi_loader: gop: fixes for CONFIG_DM_VIDEO without CONFIG_LCD")
Reported-by: Tom Rini <trini@konsulko.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
diff --git a/lib/efi_loader/efi_gop.c b/lib/efi_loader/efi_gop.c
index 806cfae..e063e0c 100644
--- a/lib/efi_loader/efi_gop.c
+++ b/lib/efi_loader/efi_gop.c
@@ -155,7 +155,7 @@
 	row = panel_info.vl_row;
 	fb_base = gd->fb_base;
 	fb_size = lcd_get_size(&line_len);
-	fb = gd->fb_base;
+	fb = (void*)gd->fb_base;
 #endif
 
 	switch (bpix) {