sparc: fix unknown escape sequence warnings

I don't know what exactly the code was going for, but the object code
is the same before/after my change, and in looking at the env strings,
this seems to be OK.

Otherwise gcc warns:
cc1: warning: unknown escape sequence: '\$'
cc1: warning: unknown escape sequence: '\)'
cc1: warning: unknown escape sequence: '\040'
cc1: warning: unknown escape sequence: '\$'
cc1: warning: unknown escape sequence: '\)'

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
diff --git a/include/configs/gr_xc3s_1500.h b/include/configs/gr_xc3s_1500.h
index 7e8e6f5..5006322 100644
--- a/include/configs/gr_xc3s_1500.h
+++ b/include/configs/gr_xc3s_1500.h
@@ -91,7 +91,7 @@
 		"bootm ${kernel_addr} ${ramdisk_addr}\0"		\
 	"net_nfs=tftp 40000000 ${bootfile};run nfsargs addip;bootm\0"	\
 	"scratch=40200000\0"					\
-	"getkernel=tftpboot \$\(scratch\)\ \$\(bootfile\)\0" \
+	"getkernel=tftpboot $(scratch) $(bootfile)\0" \
 	"bootargs=console=ttyS0,38400 root=/dev/nfs rw nfsroot=192.168.0.20:/export/rootfs ip=192.168.0.206:192.168.0.20:192.168.0.1:255.255.255.0:grxc3s1500_daniel:eth0\0" \
 	""