remove obsolete patch

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@5863 3c298f89-4303-0410-b956-a3cf2f4a3e73

target/linux/rb532-2.6/patches/230-dma_limit.patch

@@ -1,13 +0,0 @@
-diff -urN linux.old/arch/mips/mm/init.c linux.dev/arch/mips/mm/init.c
---- linux.old/arch/mips/mm/init.c	2006-06-08 20:21:20.000000000 +0200
-+++ linux.dev/arch/mips/mm/init.c	2006-06-08 20:19:40.000000000 +0200
-@@ -149,7 +149,7 @@
- 	kmap_init();
- #endif
- 
--	max_dma = virt_to_phys((char *)MAX_DMA_ADDRESS) >> PAGE_SHIFT;
-+	max_dma = virt_to_phys((char *) (256 * 1024 * 1024)) >> PAGE_SHIFT;
- 	low = max_low_pfn;
- 	high = highend_pfn;
- 
-