Drop unsupported prebuilt kernels

The hikey board is not supported any more in AOSP, but keep the 4.14 and
4.19 kernels for now as Linaro is still testing them.

Drop any kernel prior to 4.14 as these will not be supported by the next
Android release.

Change-Id: I58718952f22ec6df535c0447a3e914b13763655d
Signed-off-by: Alistair Delva <adelva@google.com>
diff --git a/Image.gz-dtb-4.4 b/Image.gz-dtb-4.4
deleted file mode 100644
index 8915304..0000000
--- a/Image.gz-dtb-4.4
+++ /dev/null
Binary files differ
diff --git a/Image.gz-dtb-4.9 b/Image.gz-dtb-4.9
deleted file mode 100644
index 7be28d8..0000000
--- a/Image.gz-dtb-4.9
+++ /dev/null
Binary files differ
diff --git a/Image.gz-dtb-hikey960-4.4 b/Image.gz-dtb-hikey960-4.4
deleted file mode 100644
index bf9195e..0000000
--- a/Image.gz-dtb-hikey960-4.4
+++ /dev/null
Binary files differ
diff --git a/Image.gz-dtb-hikey960-4.9 b/Image.gz-dtb-hikey960-4.9
deleted file mode 100644
index 87ad002..0000000
--- a/Image.gz-dtb-hikey960-4.9
+++ /dev/null
Binary files differ
diff --git a/hi3660-hikey960.dtb-4.4 b/hi3660-hikey960.dtb-4.4
deleted file mode 100644
index 7d7e6d8..0000000
--- a/hi3660-hikey960.dtb-4.4
+++ /dev/null
Binary files differ
diff --git a/hi3660-hikey960.dtb-4.9 b/hi3660-hikey960.dtb-4.9
deleted file mode 100644
index 5d5cd47..0000000
--- a/hi3660-hikey960.dtb-4.9
+++ /dev/null
Binary files differ
diff --git a/hi6220-hikey.dtb-4.4 b/hi6220-hikey.dtb-4.4
deleted file mode 100644
index 654d8a1..0000000
--- a/hi6220-hikey.dtb-4.4
+++ /dev/null
Binary files differ
diff --git a/hi6220-hikey.dtb-4.9 b/hi6220-hikey.dtb-4.9
deleted file mode 100644
index 647e5d8..0000000
--- a/hi6220-hikey.dtb-4.9
+++ /dev/null
Binary files differ