mc146818rtc: Remove the hyphen to build on NetBSD and Darwin

http://netbsd.gw.com/cgi-bin/man-cgi?date++NetBSD-current
The NetBSD manual tells us the date in NetBSD doesn't take any flags
to enable or disable padding in the format.

By default, date pads numeric fields with zeroes. This will convert the
number to octal one. So add "0x" to convert it to BCD directly.

Change-Id: Icd44312acf01b8232f1da1fbaa70630d09007b40
Signed-off-by: Zheng Bao <zheng.bao@amd.com>
Signed-off-by: zbao <fishbaozi@gmail.com>
Reviewed-on: http://review.coreboot.org/1804
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Anton Kochkov <anton.kochkov@gmail.com>
diff --git a/Makefile.inc b/Makefile.inc
index 71fdbc2..f85bbda 100644
--- a/Makefile.inc
+++ b/Makefile.inc
@@ -179,10 +179,10 @@
 	printf "#define COREBOOT_VERSION \"$(KERNELVERSION)\"\n" >> $(obj)/build.ht
 	printf "#define COREBOOT_EXTRA_VERSION \"$(COREBOOT_EXTRA_VERSION)\"\n" >> $(obj)/build.ht
 	printf "#define COREBOOT_BUILD \"`LANG= date`\"\n" >> $(obj)/build.ht
-	printf "#define COREBOOT_BUILD_YEAR `LANG= date +"%-y"`\n" >> $(obj)/build.ht
-	printf "#define COREBOOT_BUILD_MONTH `LANG= date +"%-m"`\n" >> $(obj)/build.ht
-	printf "#define COREBOOT_BUILD_DAY `LANG= date +"%-d"`\n" >> $(obj)/build.ht
-	printf "#define COREBOOT_BUILD_WEEKDAY `LANG= date +"%-w"`\n" >> $(obj)/build.ht
+	printf "#define COREBOOT_BUILD_YEAR_BCD 0x`LANG= date +"%y"`\n" >> $(obj)/build.ht
+	printf "#define COREBOOT_BUILD_MONTH_BCD 0x`LANG= date +"%m"`\n" >> $(obj)/build.ht
+	printf "#define COREBOOT_BUILD_DAY_BCD 0x`LANG= date +"%d"`\n" >> $(obj)/build.ht
+	printf "#define COREBOOT_BUILD_WEEKDAY_BCD 0x`LANG= date +"%w"`\n" >> $(obj)/build.ht
 	printf "#define COREBOOT_DMI_DATE \"`LANG= date +"%m/%d/%Y"`\"\n" >> $(obj)/build.ht
 	printf "\n" >> $(obj)/build.ht
 	printf "#define COREBOOT_COMPILER \"$(shell LANG= $(CC) --version | head -n1)\"\n" >> $(obj)/build.ht