Bump buildroot to 2019.02

bsp/buildroot/docs/manual/adding-packages-directory.txt

@@ -46,9 +46,11 @@ is as follows:
 
 1. The type of option: +bool+, +string+... with the prompt
 2. If needed, the +default+ value(s)
-3. Any dependency of the +depends on+ form
-4. Any dependency of the +select+ form
-5. The help keyword and help text.
+3. Any dependencies on the target in +depends on+ form
+4. Any dependencies on the toolchain in +depends on+ form
+5. Any dependencies on other packages in +depends on+ form
+6. Any dependency of the +select+ form
+7. The help keyword and help text.
 
 You can add other sub-options into a +if BR2_PACKAGE_LIBFOO...endif+
 statement to configure particular things in your software. You can look at
@@ -292,13 +294,13 @@ use in the comment.
 
 * Kernel headers
 ** Dependency symbol: +BR2_TOOLCHAIN_HEADERS_AT_LEAST_X_Y+, (replace
-   +X_Y+ with the proper version, see +toolchain/toolchain-common.in+)
+   +X_Y+ with the proper version, see +toolchain/Config.in+)
 ** Comment string: +headers >= X.Y+ and/or `headers <= X.Y` (replace
    +X.Y+ with the proper version)
 
 * GCC version
 ** Dependency symbol: +BR2_TOOLCHAIN_GCC_AT_LEAST_X_Y+, (replace
-   +X_Y+ with the proper version, see +toolchain/toolchain-common.in+)
+   +X_Y+ with the proper version, see +toolchain/Config.in+)
 ** Comment string: +gcc >= X.Y+ and/or `gcc <= X.Y` (replace
    +X.Y+ with the proper version)
 
@@ -444,6 +446,13 @@ contains the hashes of the downloaded files for the +libfoo+
 package. The only reason for not adding a +.hash+ file is when hash
 checking is not possible due to how the package is downloaded.
 
+When a package has a version selection choice, then the hash file may be
+stored in a subdirectory named after the version, e.g.
++package/libfoo/1.2.3/libfoo.hash+. This is especially important if the
+different versions have different licensing terms, but they are stored
+in the same file. Otherwise, the hash file should stay in the package's
+directory.
+
 The hashes stored in that file are used to validate the integrity of the
 downloaded files and of the license files.